An eye focusing problem that is unrelated to aging changes in the lens of the eye.
Lazy eye, or amblyopia, is the loss or lack of development of central vision in one eye that is unrelated to any eye health problem and is not correctable with lenses. It can result from a failure to use both eyes together. Lazy eye is often associated with crossed-eyes or a large difference in the degree of nearsightedness or farsightedness between the two eyes. It usually develops before the age of 6, and it does not affect side vision.
Symptoms may include noticeably favoring one eye or a tendency to bump into objects on one side. Symptoms are not always obvious.
Treatment for lazy eye may include a combination of prescription lenses, prisms, vision therapy and eye patching. Vision therapy teaches the two eyes how to work together, which helps prevent lazy eye from reoccurring.
Early diagnosis increases the chance for a complete recovery. This is one reason why the American Optometric Association recommends that children have a comprehensive optometric examination by the age of 6 months and again at age 3. Lazy eye will not go away on its own. If not diagnosed until the pre-teen, teen or adult years, treatment takes longer and is often less effective.
Early diagnosis increases the chance for a complete recovery.
Astigmatism is a vision condition that causes blurred vision due either to the irregular shape of the cornea, the clear front cover of the eye, or sometimes the curvature of the lens inside the eye. An irregular shaped cornea or lens prevents light from focusing properly on the retina, the light sensitive surface at the back of the eye. As a result, vision becomes blurred at any distance.
Astigmatism is a very common vision condition. Most people have some degree of astigmatism. Slight amounts of astigmatism usually don’t affect vision and don’t require treatment. However, larger amounts cause distorted or blurred vision, eye discomfort and headaches.
Astigmatism frequently occurs with other vision conditions like nearsightedness (myopia) and farsightedness (hyperopia). Together these vision conditions are referred to as refractive errors because they affect how the eyes bend or “refract” light.
The specific cause of astigmatism is unknown. It can be hereditary and is usually present from birth. It can change as a child grows and may decrease or worsen over time.
A comprehensive optometric examination will include testing for astigmatism. Depending on the amount present, your optometrist can provide eyeglasses or contact lenses that correct the astigmatism by altering the way light enters your eyes.
Another option for treating astigmatism uses a corneal modification procedure called orthokeratology (ortho-k). It is a painless, non-invasive procedure that involves wearing a series of specially designed rigid contact lenses to gradually reshape the curvature of the cornea.
Laser surgery is also a possible treatment option for some types of astigmatism. It changes the shape of the cornea by removing a small amount of eye tissue. This is done using a highly focused laser beam on the surface of the eye.
What causes astigmatism?
When the cornea or lens of an eye is irregularly shaped, vision may be out of focus at any distance.
Astigmatism occurs due to the irregular shape of the cornea or the lens inside the eye. The cornea and lens are primarily responsible for properly focusing light entering your eyes allowing you to see things clearly.
The curvature of the cornea and lens causes light entering the eye to be bent in order to focus it precisely on the retina at the back of the eye. In astigmatism, the surface of the cornea or lens has a somewhat different curvature in one direction than another. In the case of the cornea, instead of having a round shape like a basketball, the surface of the cornea is more like a football. As a result, the eye is unable to focus light rays to a single point causing vision to be out of focus at any distance.
Sometimes astigmatism may develop following an eye injury or eye surgery. There is also a relatively rare condition called keratoconus where the cornea becomes progressively thinner and cone shaped. This results in a large amount of astigmatism resulting in poor vision that cannot be clearly corrected with spectacles. Keratoconus usually requires contact lenses for clear vision, and it may eventually progress to a point where a corneal transplant is necessary.
How is astigmatism diagnosed?
A phoropter and a retinoscope are instruments commonly used by optometrists to measure refraction.
Astigmatism can be diagnosed through a comprehensive eye examination. Testing for astigmatism measures how the eyes focus light and determines the power of any optical lenses needed to compensate for reduced vision. This examination may include:
Visual acuity – As part of the testing, you’ll be asked to read letters on a distance chart. This test measures visual acuity, which is written as a fraction such as 20/40. The top number is the standard distance at which testing is done, twenty feet. The bottom number is the smallest letter size you were able to read. A person with 20/40 visual acuity would have to get within 20 feet of a letter that should be seen at forty feet in order to see it clearly. Normal distance visual acuity is 20/20.
Keratometry – A keratometer is the primary instrument used to measure the curvature of the cornea. By focusing a circle of light on the cornea and measuring its reflection, it is possible to determine the exact curvature of the cornea’s surface. This measurement is particularly critical in determining the proper fit for contact lenses. A more sophisticated procedure called corneal topography may be performed in some cases to provide even more detail of the shape of the cornea.
Refraction – Using an instrument called a phoropter, your optometrist places a series of lenses in front of your eyes and measures how they focus light. This is performed using a hand held lighted instrument called a retinoscope or an automated instrument that automatically evaluates the focusing power of the eye. The power is then refined by patient’s responses to determine the lenses that allow the clearest vision.
Using the information obtained from these tests, your optometrist can determine if you have astigmatism. These findings, combined with those of other tests performed, will allow the optometrist to determine the power of any lens correction needed to provide clear, comfortable vision, and discuss options for treatment.
How is astigmatism treated?
Persons with astigmatism have several options available to regain clear vision. They include:
laser and other refractive surgery procedures
Eyeglasses are a common form of correction for persons with astigmatism.
Eyeglasses are the primary choice of correction for persons with astigmatism. They will contain a special cylindrical lens prescription to compensate for the astigmatism. This provides for additional lens power in only specific meridians of the lens. An example of a prescription for astigmatism for one eye would be -1.00 -1.25 X 180. The middle number (-1.25) is the lens power for correction of the astigmatism. The “X 180” designates the placement (axis) of the lens power. The first number (-1.00) indicates that this prescription also includes a correction for nearsightedness in addition to astigmatism.
Generally, a single vision lens is prescribed to provide clear vision at all distances. However, for patients over about age 40 who have the condition called presbyopia, a bifocal or progressive addition lens may be needed. These provide different lens powers to see clearly in the distance and to focus effectively for near vision work.
A wide variety of lens types and frame designs are now available for patients of all ages. Eyeglasses are no longer just a medical device that provides needed vision correction. Eyeglass frames are available in a many shapes, sizes, colors and materials that not only allow for correction of vision, but also enhance appearance.
For some individuals, contact lenses can offer better vision than eyeglasses. They may provide clearer vision and a wider field of view. However, since contact lenses are worn directly on the eyes, they require regular cleaning and care to safeguard eye health.
Soft contact lenses conform to the shape of the eye, therefore standard soft lenses may not be effective in correcting astigmatism. However, special toric soft contact lenses are available to provide a correction for many types of astigmatism. Because rigid gas permeable contact lenses maintain their regular shape while on the cornea, they offer an effective way to compensate for the cornea’s irregular shape and improve vision for persons with astigmatism and other refractive errors.
Orthokeratology (Ortho-K) involves the fitting of a series of rigid contact lenses to reshape the cornea, the front outer cover of the eye. The contact lenses are worn for limited periods, such as overnight, and then removed. Persons with moderate amounts of astigmatism may be able to temporarily obtain clear vision without lenses for most of their daily activities. Orthokeratology does not permanently improve vision and if you stop wearing the retainer lenses, your vision may return to its original condition.
Astigmatism can also be corrected by reshaping the cornea using a highly focused laser beam of light. Two commonly used procedures are photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK).
PRK removes tissue from the superficial and inner layers of the cornea. LASIK does not remove tissue from the surface of the cornea, but only from its inner layer. To do this, a section of outer corneal surface is cut and folded back to expose the inner tissue. Then a laser is used to remove the precise amount of tissue needed and the flap of outer tissue is placed back in position to heal. Both procedures allow light to focus on the retina by altering the shape of the cornea.
Individuals with astigmatism have a wide range of options to correct their vision problem. In consultation with your optometrist, you can select the treatment that best meets your visual and lifestyle needs.
Blepharitis is an inflammation of the eyelids causing red, irritated, itchy eyelids and the formation of dandruff-like scales on eyelashes. It is a common eye disorder caused by either bacterial or a skin condition such as dandruff of the scalp or acne rosacea. It affects people of all ages. Although uncomfortable, blepharitis is not contagious and generally does not cause any permanent damage to eyesight.
Blepharitis is classified into two types:
Anterior blepharitis occurs at the outside front edge of the eyelid where the eyelashes are attached.
Posterior blepharitis affects the inner edge of the eyelid that comes in contact with the eyeball.
Individuals with blepharitis may experience a gritty or burning sensation in their eyes, excessive tearing, itching, red and swollen eyelids, dry eyes, or crusting of the eyelids. For some people, blepharitis causes only minor irritation and itching. However, it can lead to more severe signs and symptoms such as blurring of vision, missing or misdirected eyelashes, and inflammation of other eye tissue, particularly the cornea.
In many cases, good eyelid hygiene and a regular cleaning routine can control blepharitis. This includes frequent scalp and face washing, using warm compresses to soak the eyelids, and doing eyelid scrubs. In cases where a bacterial infection is the cause, various antibiotics and other medications may be prescribed along with eyelid hygiene.
What causes blepharitis?
Blepharitis can appear as greasy flakes or scales around the base of the eyelashes.
Anterior blepharitis is commonly caused by bacteria (staphylococcal blepharits) or dandruff of the scalp and eyebrows (seborrheic blepharitis). It may also occur due to a combination of factors, or less commonly may be the result of allergies or an infestation of the eyelashes.
Posterior blepharitis can be caused by irregular oil production by the glands of the eyelids (meibomian blepharitis) which creates a favorable environment for bacterial growth. It can also develop as a result of other skin conditions such as acne rosacea and scalp dandruff.
How is blepharitis diagnosed?
Blepharitis can be diagnosed through a comprehensive eye examination. Testing, with special emphasis on evaluation of the eyelids and front surface of the eyeball, may include:
Patient history to determine any symptoms the patient is experiencing and the presence of any general health problems that may be contributing to the eye problem.
External examination of the eye, including lid structure, skin texture and eyelash appearance.
Evaluation of the lid margins, base of the eyelashes and meibomian gland openings using bright light and magnification.
Evaluation of the quantity and quality of tears for any abnormalities.
A differentiation among the various types of blepharitis can often be made based on the appearance of the eyelid margins:
Staphyloccal blepharitis patients frequently exhibit mild sticking together of the lids, thickened lid margins, and missing and misdirected eyelashes.
Seborrheic blepharitis appears as greasy flakes or scales around the base of eyelashes and a mild redness of the eyelids.
Ulcerative blepharitis is characterized by matted, hard crusts around the eyelashes that when removed, leave small sores that ooze and bleed. There may also be a loss of eyelashes, distortion of the front edges of the eyelids and chronic tearing. In severe cases, the cornea, the transparent front covering of the eyeball, may also become inflamed.
Meibomian blepharitis is evident by blockage of the oil glands in the eyelids, poor quality of tears, and redness of the lining of the eyelids.
Using the information obtained from testing, your optometrist can determine if you have blepharitis and advise you on treatment options.
How is blepharitis treated?
Treatment depends on the specific type of blepharitis. The key to treating most types of blepharitis is keeping the lids clean and free of crusts.
Limiting or stopping the use of eye makeup when treating blepharitis is often recommended, as its use will make lid hygiene more difficult.
Warm compresses can be applied to loosen the crusts, followed by gentle scrubbing of the eyes with a mixture of water and baby shampoo or an over-the-counter lid cleansing product. In cases involving bacterial infection, an antibiotic may also be prescribed.
If the glands in the eyelids are blocked, the eyelids may need to be massaged to clean out oil accumulated in the eyelid glands.
Artificial tear solutions or lubricating ointments may be prescribed in some cases.
Use of an anti-dandruff shampoo on the scalp can help.
Limiting or stopping the use of eye makeup is often recommended, as its use will make lid hygiene more difficult.
If you wear contact lenses, you may have to temporarily discontinue wearing them during treatment.
Some cases of blepharitis may require more complex treatment plans. Blepharitis seldom disappears completely. Even with successful treatment, relapses may occur.
Blepharitis seldom disappears completely. Even with successful treatment, relapses may occur.
An important part of controlling blepharitis involves treatment at home.
Directions for a Warm Soak of the Eyelids:
Wash your hands thoroughly.
Moisten a clean washcloth with warm water.
Close eyes and place washcloth on eyelids for about 5 minutes, reheating the washcloth as necessary.
Repeat several times daily.
Directions for an Eyelid Scrub:
Wash your hands thoroughly.
Mix warm water and a small amount of non-irritating (baby) shampoo or use a commercially prepared lid scrub solution recommended by your optometrist.
Using a clean cloth (a different one for each eye) rub the solution back and forth across the eyelashes and edge of the closed eyelid.
Rinse with clear water.
Repeat with the other eye.
A cataract is a cloudy or opaque area in the normally clear lens of the eye. Depending upon its size and location, it can interfere with normal vision. Most cataracts develop in people over age 55, but they occasionally occur in infants and young children. Usually cataracts develop in both eyes, but one may be worse than the other. Reasearchers have linked eye-friendly nutrients such as lutein/zeaxanthin, vitamin C, vitamin E, and zinc to reducing the risk of certain eye diseases, including cataracts. For more information on the importance of good nutrition and eye health, please see the diet and nutrition section.
The lens is located inside the eye behind the iris, the colored part of the eye. The lens focuses light on the back of the eye, the retina. The lens is made of mostly proteins and water. Clouding of the lens occurs due to changes in the proteins and lens fibers.
The lens is composed of layers like an onion. The outermost is the capsule. The layer inside the capsule is the cortex, and the innermost layer is the nucleus. A cataract may develop in any of these areas and is described based on its location in the lens:
A nuclear cataract is located in the center of the lens. The nucleus tends to darken changing from clear to yellow and sometimes brown.
A cortical cataract affects the layer of the lens surrounding the nucleus. It is identified by its unique wedge or spoke appearance.
A posterior capsular cataract is found in the back outer layer of the lens. This type often develops more rapidly.
Types of Cataracts
Posterior capsular cataract
Normally, the lens focuses light on the retina, which sends the image through the optic nerve to the brain. However, if the lens is clouded by a cataract, light is scattered so the lens can no longer focus it properly, causing vision problems.
Cataracts generally form very slowly. Signs and symptoms of a cataract may include:
Blurred or hazy vision
Reduced intensity of colors
Increased sensitivity to glare from lights, particularly when driving at night
Increased difficulty seeing at night
Change in the eye’s refractive error
While the process of cataract formation is becoming more clearly understood, there is no clinically established treatment to prevent or slow their progression. In age-related cataracts, changes in vision can be very gradual. Some people may not initially recognize the visual changes. However, as cataracts worsen vision symptoms tend to increase in severity.
A chalazion is a slowly developing lump that forms due to blockage and swelling of an oil gland in the eyelid. It is more common in adults than children and occurs most frequently in persons 30 to 50 years of age.
Initially, a chalazion may appear as a red, tender, swollen area of the eyelid. However, in a few days it changes to a painless, slow growing lump in the eyelid. A chalazion often starts out very small and is barely able to be seen, but it may grow to the size of a pea. Often times they may be confused with sties, which are also areas of swelling in the eyelid.
A sty is an infection of an oil gland in the eyelid. It produces a red, swollen, painful lump on the edge or inside surface of the eyelid. Sties usually occur closer to the surface of the eyelid than do chalazia.
A chalazion is generally not due to an infection, but results from a blockage of the oil gland itself. However, a chalazion may occur as an after-effect of a sty.
Common signs or symptoms of a chalazion include:
Appearance of a painless bump or lump in the upper eyelid, or, less commonly, in the lower eyelid
Blurred vision, if the chalazion is large enough to press against the eyeball
Most chalazia disappear without treatment in several weeks to a month. However, they often recur. Rarely, they may be an indication of an infection or skin cancer.
What causes a chalazion?
A chalazion can develop when the oil produced by glands within the eyelids, called the meibomian glands, becomes thickened and is unable to flow out of the gland. The oil builds up inside the gland and forms a lump in the eyelid. Eventually the gland may break open and release the oil into the surrounding tissue causing an inflammation of the eyelid.
Risk factors for the development of a chalazion include:
Chronic blepharitis, an inflammation of the eyelids and eye lashes
How is a chalazion diagnosed?
A chalazion can be diagnosed through a comprehensive eye examination. Testing, with special emphasis on evaluation of the eyelids, may include:
Patient history to determine any symptoms the patient is experiencing and the presence of any general health problems that may be contributing to the eye problem.
External examination of the eye, including lid structure, skin texture and eyelash appearance.
Evaluation of the lid margins, base of the eyelashes and oil gland openings using bright light and magnification.
Using the information obtained from testing, your optometrist can determine if you have a chalazion and advise you on treatment options.
How is a chalazion treated?
Many chalazia require minimal medical treatment, resolving on their own in a few weeks to a month. To facilitate healing, warm compresses can be applied to the eyelid for 10 to15 minutes 4 to 6 times a day for several days. The warm compresses may help soften the hardened oil that is blocking the ducts thereby promoting drainage and healing. Lightly messaging the external area of the eyelid for several minutes each day may also help to promote drainage.
A clean soft cloth dipped in warm water and wrung out can serve as an effective compress. Remoisten the cloth frequently to keep it wet and warm. Once the chalazion drains on its own, keep the area clean and keep your hands away from your eyes.
If the chalazion does not drain and heal within a month, contact your eye doctor. Don’t attempt to squeeze or drain the chalazion yourself.
Color Vision Deficiency
Color vision deficiency is the inability to distinguish certain shades of color or in more severe cases, see colors at all. The term “color blindness” is also used to describe this visual condition, but very few people are completely color blind.
Red-green deficiency results in the inability to distinguish certain shades of red and green. Most people with color vision deficiency can see colors, but they have difficulty differentiating between
particular shades of reds and greens (most common) or
blues and yellows (less common).
People who are totally color blind, a condition called achromatopsia, can only see things as black and white or in shades of gray.
The severity of color vision deficiency can range from mild to severe depending on the cause. It will affect both eyes if it is inherited and usually just one if the cause for the deficiency is injury or illness.
Color vision is possible due to photoreceptors in the retina of the eye known as cones. These cones have light sensitive pigments that enable us to recognize color. Found in the macula, the central portion of the retina, each cone is sensitive to either red, green or blue light, which the cones recognize based upon light wavelengths.
Normally, the pigments inside the cones register differing colors and send that information through the optic nerve to the brain enabling you to distinguish countless shades of color. But if the cones lack one or more light sensitive pigments, you will be unable to see one or more of the three primary colors thereby causing a deficiency in your color perception.
The most common form of color deficiency is red-green. This does not mean that people with this deficiency cannot see these colors at all; they simply have a harder time differentiating between them. The difficulty they have in correctly identifying them depends on how dark or light the colors are.
Another form of color deficiency is blue-yellow. This is a rarer and more severe form of color vision loss than red-green since persons with blue-yellow deficiency frequently have red-green blindness too. In both cases, it is common for people with color vision deficiency to see neutral or gray areas where a particular color should appear.
Computer Vision Syndrome
A group of eye and vision-related problems that result from prolonged computer use.
Conjunctivitis is an inflammation or infection of the conjunctiva, the thin transparent layer of tissue that lines the inner surface of the eyelid and covers the white part of the eye. Conjunctivitis, often called “pink eye,” is a common eye disease, especially in children. It may affect one or both eyes. Some forms of conjunctivitis can be highly contagious and easily spread in schools and at home. While conjunctivitis is usually a minor eye infection, sometimes it can develop into a more serious problem.
Conjunctivitis may be caused by a viral or bacterial infection. It can also occur due to an allergic reaction to irritants in the air like pollen and smoke, chlorine in swimming pools, and ingredients in cosmetics or other products that come in contact with the eyes. Sexually transmitted diseases like Chlamydia and gonorrhea are less common causes of conjunctivitis.
People with conjunctivitis may experience the following symptoms:
A gritty feeling in one or both eyes
Itching or burning sensation in one or both eyes
Discharge coming from one or both eyes
Pink discoloration to the whites of one or both eyes
Increased sensitivity to light
What causes conjunctivitis?
Allergic Conjunctivitis occurs more commonly among people who already have seasonal allergies.
The cause of conjunctivitis varies depending on the offending agent. There are three main categories of conjunctivitis: allergic, infectious and chemical:
Allergic Conjunctivitis occurs more commonly among people who already have seasonal allergies. At some point they come into contact with a substance that triggers an allergic reaction in their eyes.
Giant Papillary Conjunctivitis is a type of allergic conjunctivitis caused by the chronic presence of a foreign body in the eye. This condition occurs predominantly with people who wear hard or rigid contact lenses, wear soft contact lenses that are not replaced frequently, have an exposed suture on the surface or the eye, or have a glass eye.
Bacterial Conjunctivitis is an infection most often caused by staphylococcal or streptococcal bacteria from your own skin or respiratory system. Infection can also occur by transmittal from insects, physical contact with other people, poor hygiene (touching the eye with unclean hands), or by use of contaminated eye makeup and facial lotions.
Viral Conjunctivitis is most commonly caused by contagious viruses associated with the common cold. The primary means of contracting this is through exposure to coughing or sneezing by persons with upper respiratory tract infections. It can also occur as the virus spreads along the body’s own mucous membranes connecting lungs, throat, nose, tear ducts, and conjunctiva.
Ophthalmia Neonatorum is a severe form of bacterial conjunctivitis that occurs in newborn babies. This is a serious condition that could lead to permanent eye damage unless it is treated immediately. Ophthalmia neonatorum occurs when an infant is exposed to Chlamydia or gonorrhea while passing through the birth canal.
Chemical Conjunctivitis can be caused by irritants like air pollution, chlorine in swimming pools, and exposure to noxious chemicals.
How is conjunctivitis diagnosed?
Conjunctivitis can be diagnosed through a comprehensive eye examination.
Conjunctivitis can be diagnosed through a comprehensive eye examination. Testing, with special emphasis on evaluation of the conjunctiva and surrounding tissues, may include:
Patient history to determine the symptoms the patient is experiencing, when the symptoms began, and the presence of any general health or environmental conditions that may be contributing to the problem.
Visual acuity measurements to determine the extent to which vision may be affected.
Evaluation of the conjunctiva and external eye tissue using bright light and magnification.
Evaluation of the inner structures of the eye to ensure that no other tissues are affected by the condition.
Supplemental testing may include taking cultures or smears of conjunctival tissue, particularly in cases of chronic conjunctivitis or when the condition is not responding to treatment.
Using the information obtained from these tests, your optometrist can determine if you have conjunctivitis and advise you on treatment options.
How is conjunctivitis treated?
Treatment of conjunctivitis is directed at three main goals:
To increase patient comfort.
To reduce or lessen the course of the infection or inflammation.
To prevent the spread of the infection in contagious forms of conjunctivitis.
The appropriate treatment for conjunctivitis depends on its cause:
Allergic conjunctivitis – The first step should be to remove or avoid the irritant, if possible. Cool compresses and artificial tears sometimes relieve discomfort in mild cases. In more severe cases, non-steroidal anti-inflammatory medications and antihistamines may be prescribed. Cases of persistent allergic conjunctivitis may also require topical steroid eye drops.
Bacterial conjunctivitis – This type of conjunctivitis is usually treated with antibiotic eye drops or ointments. Improvement can occur after three or four days of treatment, but the entire course of antibiotics needs to be used to prevent recurrence.
Viral Conjunctivitis – There are no available drops or ointments to eradicate the virus for this type of conjunctivitis. Antibiotics will not cure a viral infection. Like a common cold, the virus just has to run its course, which may take up to two or three weeks in some cases. The symptoms can often be relieved with cool compresses and artificial tear solutions. For the worst cases, topical steroid drops may be prescribed to reduce the discomfort from inflammation, but do not shorten the course of the infection. Some doctors may perform an ophthalmic iodine eye wash in the office in hopes of shortening the course of the infection. This newer treatment has not been well studied yet, therefore no conclusive evidence of the success exists.
Chemical Conjunctivitis – Treatment for chemical conjunctivitis requires careful flushing of the eyes with saline and may require topical steroids. The more acute chemical injuries are medical emergencies, particularly alkali burns, which can lead to severe scarring, intraocular damage or even loss of the eye.
Contact Lens Wearers
Contact lens wearers may need to discontinue wearing their lenses while the conjunctivitis is active.
Contact lens wearers may need to discontinue wearing their lenses while the condition is active. Your doctor can advise you on the need for temporary restrictions on contact lens wear.
If the conjunctivitis developed due to wearing contact lenses, your eye doctor may recommend that you switch to a different type of contact lens or disinfection solution. Your optometrist might need to alter your contact lense prescription to a type of lens that you replace more frequently to prevent the conjunctivitis from recurring.
Practicing good hygiene is the best way to control the spread of conjunctivitis. Once an infection has been diagnosed, follow these steps:
Don’t touch your eyes with your hands.
Wash your hands thoroughly and frequently.
Change your towel and washcloth daily, and don’t share them with others.
Discard eye cosmetics, particularly mascara.
Don’t use anyone else’s eye cosmetics or personal eye-care items.
Follow your eye doctor’s instructions on proper contact lens care.
You can soothe the discomfort of viral or bacterial conjunctivitis by applying warm compresses to your affected eye or eyes. To make a compress, soak a clean cloth in warm water and wring it out before applying it gently to your closed eyelids.
For allergic conjunctivitis, avoid rubbing your eyes. Instead of warm compresses, use cool compresses to soothe your eyes. Over the counter eye drops are available. Antihistamine eye drops should help to alleviate the symptoms, and lubricating eye drops help to rinse the allergen off of the surface of the eye.
See your doctor of optometry when you experience conjunctivitis to help diagnose the cause and the proper course of action.
An eye coordination problem in which the eyes have a tendency to drift outward when reading or doing close work.
A cut or scratch on the cornea, the clear front cover of the eye.
A condition in which both eyes do not look at the same place at the same time. See also Amblyopia.
Diabetic retinopathy is a condition occurring in persons with diabetes, which causes progressive damage to the retina, the light sensitive lining at the back of the eye. It is a serious sight-threatening complication of diabetes.
Diabetes is a disease that interferes with the body’s ability to use and store sugar, which can cause many health problems. Too much sugar in the blood can cause damage throughout the body, including the eyes. Over time, diabetes affects the circulatory system of the retina.
Diabetic retinopathy is the result of damage to the tiny blood vessels that nourish the retina. They leak blood and other fluids that cause swelling of retinal tissue and clouding of vision. The condition usually affects both eyes. The longer a person has diabetes, the more likely they will develop diabetic retinopathy. If left untreated, diabetic retinopathy can cause blindness.
Symptoms of diabetic retinopathy include:
Seeing spots or floaters in your field of vision
Having a dark or empty spot in the center of your vision
Difficulty seeing well at night
In patients with diabetes, prolonged periods of high blood sugar can lead to the accumulation of fluid in the lens inside the eye that controls eye focusing. This changes the curvature of the lens and results in the development of symptoms of blurred vision. The blurring of distance vision as a result of lens swelling will subside once the blood sugar levels are brought under control. Better control of blood sugar levels in patients with diabetes also slows the onset and progression of diabetic retinopathy.
Often there are no visual symptoms in the early stages of diabetic retinopathy. That is why the American Optometric Association recommends that everyone with diabetes have a comprehensive dilated eye examination once a year. Early detection and treatment can limit the potential for significant vision loss from diabetic retinopathy.
Treatment of diabetic retinopathy varies depending on the extent of the disease. It may require laser surgery to seal leaking blood vessels or to discourage new leaky blood vessels from forming. Injections of medications into the eye may be needed to decrease inflammation or stop the formation of new blood vessels. In more advanced cases, a surgical procedure to remove and replace the gel-like fluid in the back of the eye, called the vitreous, may be needed. A retinal detachment, defined as a separation of the light-receiving lining in the back of the eye, resulting from diabetic retinopathy, may also require surgical repair.
If you are a diabetic, you can help prevent or slow the development of diabetic retinopathy by taking your prescribed medication, sticking to your diet, exercising regularly, controlling high blood pressure and avoiding alcohol and smoking.
What causes diabetic retinopathy?
Non-proliferative diabetic retinopathy (NPDR) is the early state of the disease in which symptoms will be mild or non-existent. In NPDR, the blood vessels in the retina are weakened causing tiny bulges called microanuerysms to protrude from their walls.
Proliferative diabetic retinopathy (PDR) is the more advanced form of the disease. At this stage, new fragile blood vessels can begin to grow in the retina and into the vitreous, the gel-like fluid that fills the back of the eye. The new blood vessel may leak blood into the vitreous, clouding vision.
Diabetic retinopathy is the result of damage caused by diabetes to the small blood vessels located in the retina. Blood vessels damaged from diabetic retinopathy can cause vision loss:
Fluid can leak into the macula, the area of the retina which is responsible for clear central vision. Although small, the macula is the part of the retina that allows us to see colors and fine detail. The fluid causes the macula to swell, resulting in blurred vision.
In an attempt to improve blood circulation in the retina, new blood vessels may form on its surface. These fragile, abnormal blood vessels can leak blood into the back of the eye and block vision.
Diabetic retinopathy is classified into two types:
Non-proliferative diabetic retinopathy (NPDR) is the early state of the disease in which symptoms will be mild or non-existent. In NPDR, the blood vessels in the retina are weakened causing tiny bulges called microanuerysms to protrude from their walls. The microanuerysms may leak fluid into the retina, which may lead to swelling of the macula.
Proliferative diabetic retinopathy (PDR) is the more advanced form of the disease. At this stage, circulation problems cause the retina to become oxygen deprived. As a result new fragile blood vessels can begin to grow in the retina and into the vitreous, the gel-like fluid that fills the back of the eye. The new blood vessel may leak blood into the vitreous, clouding vision. Other complications of PDR include detachment of the retina due to scar tissue formation and the development of glaucoma. Glaucoma is an eye disease defined as progressive damage to the optic nerve. In cases of proliferative diabetic retinopathy, the cause of this nerve damage is due to extremely high pressure in the eye. If left untreated, proliferative diabetic retinopathy can cause severe vision loss and even blindness.
Risk factors for diabetic retinopathy include:
Diabetes — people with Type 1 or Type 2 diabetes are at risk for the development of diabetic retinopathy. The longer a person has diabetes, the more likely they are to develop diabetic retinopathy, particularly if the diabetes is poorly controlled.
Race — Hispanic and African Americans are at greater risk for developing diabetic retinopathy.
Medical conditions — persons with other medical conditions such as high blood pressure and high cholesterol are at greater risk.
Pregnancy — pregnant women face a higher risk for developing diabetes and diabetic retinopathy. If gestational diabetes develops, the patient is at much higher risk of developing diabetes as they age.
How is diabetic retinopathy diagnosed?
Diabetic retinopathy can be diagnosed through a comprehensive eye examination.
Diabetic retinopathy can be diagnosed through a comprehensive eye examination. Testing, with special emphasis on evaluation of the retina and macula, may include:
Patient history to determine vision difficulties experienced by the patient, presence of diabetes, and other general health concerns that may be affecting vision
Visual acuity measurements to determine the extent to which central vision has been affected
Refraction to determine the need for changes in an eyeglass prescription
Evaluation of the ocular structures, including the evaluation of the retina through a dilated pupil
Measurement of the pressure within the eye
Supplemental testing may include:
Retinal photography or tomography to document current status of the retina
Fluorescein angiography to evaluate abnormal blood vessel growth
How is diabetic retinopathy treated?
Laser treatment (photocoagulation) is used to stop the leakage of blood and fluid into the retina. A laser beam of light can be used to create small burns in areas of the retina with abnormal blood vessels to try to seal the leaks.
Treatment for diabetic retinopathy depends on the stage of the disease and is directed at trying to slow or stop the progression of the disease.
In the early stages of Non-proliferative Diabetic Retinopathy, treatment other than regular monitoring may not be required. Following your doctor’s advice for diet and exercise and keeping blood sugar levels well-controlled can help control the progression of the disease.
If the disease advances, leakage of fluid from blood vessels can lead to macular edema. Laser treatment (photocoagulation) is used to stop the leakage of blood and fluid into the retina. A laser beam of light can be used to create small burns in areas of the retina with abnormal blood vessels to try to seal the leaks.
When blood vessel growth is more widespread throughout the retina, as in proliferative diabetic retinopathy, a pattern of scattered laser burns is created across the retina. This causes abnormal blood vessels to shrink and disappear. With this procedure, some side vision may be lost in order to safeguard central vision.
Some bleeding into the vitreous gel may clear up on its own. However, if significant amounts of blood leak into the vitreous fluid in the eye, it will cloud vision and can prevent laser photocoagulation from being used. A surgical procedure called a vitrectomy may be used to remove the blood-filled vitreous and replace it with a clearfluid to maintain the normal shape and health of the eye.
Persons with diabetic retinopathy can suffer significant vision loss. Special low vision devices such as telescopic and microscopic lenses, hand and stand magnifiers, and video magnification systems can be prescribed to make the most of remaining vision.
Dry eye is a condition in which there are insufficient tears to lubricate and nourish the eye. Tears are necessary for maintaining the health of the front surface of the eye and for providing clear vision. People with dry eyes either do not produce enough tears or have a poor quality of tears. Dry eye is a common and often chronic problem, particularly in older adults.
With each blink of the eyelids, tears are spread across the front surface of the eye, known as the cornea. Tears provide lubrication, reduce the risk of eye infection, wash away foreign matter in the eye, and keep the surface of the eyes smooth and clear. Excess tears in the eyes flow into small drainage ducts, in the inner corners of the eyelids, which drain in the back of the nose.
Dry eyes can result from an improper balance of tear production and drainage.
Inadequate amount of tears – Tears are produced by several glands in and around the eyelids. Tear production tends to diminish with age, with various medical conditions, or as a side effect of certain medicines. Environmental conditions such as wind and dry climates can also affect tear volume by increasing tear evaporation. When the normal amount of tear production decreases or tears evaporate too quickly from the eyes, symptoms of dry eye can develop.
Poor quality of tears – Tears are made up of three layers: oil, water, and mucus. Each component serves a function in protecting and nourishing the front surface of the eye. A smooth oil layer helps to prevent evaporation of the water layer, while the mucin layer functions in spreading the tears evenly over the surface of the eye. If the tears evaporate too quickly or do not spread evenly over the cornea due to deficiencies with any of the three tear layers, dry eye symptoms can develop.
The most common form of dry eyes is due to an inadequate amount of the water layer of tears. This condition, called keratoconjunctivitis sicca (KCS), is also referred to as dry eye syndrome.
People with dry eyes may experience symptoms of irritated, gritty, scratchy, or burning eyes, a feeling of something in their eyes, excess watering, and blurred vision. Advanced dry eyes may damage the front surface of the eye and impair vision.
Treatments for dry eyes aim to restore or maintain the normal amount of tears in the eye to minimize dryness and related discomfort and to maintain eye health.
What causes dry eyes?
The majority of people over the age of 65 experience some symptoms of dry eyes.
The development of dry eyes can have many causes. They include:
Age – dry eye is a part of the natural aging process. The majority of people over age 65 experience some symptoms of dry eyes.
Gender – women are more likely to develop dry eyes due to hormonal changes caused by pregnancy, the use of oral contraceptives, and menopause.
Medications – certain medicines, including antihistamines, decongestants, blood pressure medications and antidepressants, can reduce the amount of tears produced in the eyes.
Medical conditions – persons with rheumatoid arthritis, diabetes and thyroid problems are more likely to have symptoms of dry eyes. Also, problems with inflammation of the eyelids (blepharitis), inflammation of the surfaces of the eye, or the inward or outward turning of eyelids can cause dry eyes to develop.
Environmental conditions – exposure to smoke, wind and dry climates can increase tear evaporation resulting in dry eye symptoms. Failure to blink regularly, such as when staring at a computer screen for long periods of time, can also contribute to drying of the eyes.
Other factors – long term use of contact lenses can be a factor in the development of dry eyes. Refractive eye surgeries, such as LASIK, can cause decreased tear production and dry eyes.
How are dry eyes diagnosed?
Dry eyes can be diagnosed through a comprehensive eye examination. Testing, with special emphasis on the evaluation of the quantity and quality of tears produced by the eyes, may include:
Patient history to determine any symptoms the patient is experiencing and the presence of any general health problems, medications taken, or environmental factors that may be contributing to the dry eye problem.
External examination of the eye, including lid structure and blink dynamics.
Evaluation of the eyelids and cornea using bright light and magnification.
Measurement of the quantity and quality of tears for any abnormalities. Special dyes may be instilled in the eyes to better observe tear flow and to highlight any changes to the outer surface of the eye caused by insufficient tears.
Using the information obtained from testing, your optometrist can determine if you have dry eyes and advise you on treatment options.
How are dry eyes treated?
One of the primary approaches used to manage and treat mild cases of dry eyes is adding tears using over-the-counter artificial tear solutions.
Dry eyes can be a chronic condition, but your optometrist can prescribe treatment to keep your eyes healthy, more comfortable, and prevent your vision from being affected. The primary approaches used to manage and treat dry eyes include adding tears, conserving tears, increasing tear production, and treating the inflammation of the eyelids or eye surface that contributes to the dry eyes.
Adding tears – Mild cases of dry eyes can often be managed using over-the-counter artificial tear solutions. These can be used as often as needed to supplement natural tear production. Preservative-free artificial tear solutions are recommended because they contain fewer additives that could further irritate the eyes. However, some people may have persistent dry eyes that don’t respond to artificial tears alone. Additional steps need to be taken to treat their dry eyes.
Conserving tears – An additional approach to reducing the symptoms of dry eyes is to keep natural tears in the eyes longer. This can be done by blocking the tear ducts through which the tears normally drain. The tear ducts can be blocked with tiny silicone or gel-like plugs that can be removed, if needed. A surgical procedure to permanently close tear ducts can also be used. In either case, the goal is to keep the available tears in the eye longer to reduce problems related to dry eyes.
Increasing tear production – Prescription eye drops that help to increase production of tears can be recommended by your optometrist, as well as omega-3 fatty acid nutritional supplements.
Treatment of the contributing eyelid or ocular surface inflammation – Prescription eye drops or ointments, warm compresses and lid massage, or eyelid cleaners may be recommended to help decrease inflammation around the surface of the eyes.
Steps you can take to reduce symptoms of dry eyes include:
Remembering to blink regularly when reading or staring at a computer screen for long periods of time.
Increasing the level of humidity in the air at work and at home.
Wearing sunglasses outdoors, particularly those with wrap around frame design, to reduce exposure to drying winds and sun.
Using nutritional supplements containing essential fatty acids may help decrease dry eye symptoms in some people. Ask your optometrist if the use of dietary supplements could be of help for your dry eye problems.
Avoiding becoming dehydrated by drinking plenty of water (8 to 10 glasses) each day.
Farsightedness, or hyperopia, as it is medically termed, is a vision condition in which distant objects are usually seen clearly, but close ones do not come into proper focus. Farsightedness occurs if your eyeball is too short or the cornea has too little curvature, so light entering your eye is not focused correctly.
Common signs of farsightedness include difficulty in concentrating and maintaining a clear focus on near objects, eye strain, fatigue and/or headaches after close work, aching or burning eyes, irritability or nervousness after sustained concentration.
Common vision screenings, often done in schools, are generally ineffective in detecting farsightedness. A comprehensive optometric examination will include testing for farsightedness.
In mild cases of farsightedness, your eyes may be able to compensate without corrective lenses. In other cases, your optometrist can prescribe eyeglasses or contact lenses to optically correct farsightedness by altering the way the light enters your eyes.
Floaters & Spots
Spots (often called floaters) are small, semi-transparent or cloudy specks or particles within the vitreous, which is the clear, jelly-like fluid that fills the inside of your eyes. They appear as specks of various shapes and sizes, threadlike strands or cobwebs. Because they are within your eyes, they move as your eyes move and seem to dart away when you try to look at them directly.
Spots are often caused by small flecks of protein or other matter trapped during the formation of your eyes before birth. They can also result from deterioration of the vitreous fluid, due to aging; or from certain eye diseases or injuries.
Most spots are not harmful and rarely limit vision. But, spots can be indications of more serious problems, and you should see your optometrist for a comprehensive examination when you notice sudden changes or see increases in them.
By looking in your eyes with special instruments, your optometrist can examine the health of your eyes and determine if what you are seeing is harmless or the symptom of a more serious problem that requires treatment.
Most spots are not harmful and rarely limit vision. But, spots can be indications of more serious problems.
Glaucoma is a group of eye disorders leading to progressive damage to the optic nerve, and is characterized by loss of nerve tissue resulting in loss of vision. The optic nerve is a bundle of about one million individual nerve fibers and transmits the visual signals from the eye to the brain. The most common form of glaucoma, primary open-angle glaucoma, is associated with an increase in the fluid pressure inside the eye. This increase in pressure may cause progressive damage to the optic nerve and loss of nerve fibers. Vision loss may result. Advanced glaucoma may even cause blindness. Not everyone with high eye pressure will develop glaucoma, and many people with normal eye pressure will develop glaucoma. When the pressure inside an eye is too high for that particular optic nerve, whatever that pressure measurement may be, glaucoma will develop.
Glaucoma is the second leading cause of blindness in the U.S. It most often occurs in people over age 40, although a congenital or infantile form of glaucoma exists. People with a family history of glaucoma, African Americans over the age of 40, and Hispanics over the age of 60 are at an increased risk of developing glaucoma. Other risk factors include thinner corneas, chronic eye inflammation, and using medications that increase the pressure in the eyes.
The most common form of glaucoma, primary open-angle glaucoma, develops slowly and usually without any symptoms. Many people do not become aware they have the condition until significant vision loss has occurred. It initially affects peripheral or side vision, but can advance to central vision loss. If left untreated, glaucoma can lead to significant loss of vision in both eyes, and may even lead to blindness.
A less common type of glaucoma, acute angle closure glaucoma, usually occurs abruptly due to a rapid increase of pressure in the eye. Its symptoms may include severe eye pain, nausea, redness in the eye, seeing colored rings around lights, and blurred vision. This condition is an ocular emergency, and medical attention should be sought immediately, as severe vision loss can occur quickly.
Glaucoma cannot currently be prevented, but if diagnosed and treated early it can usually be controlled. Medication or surgery can slow or prevent further vision loss. However, vision already lost to glaucoma cannot be restored. That is why the American Optometric Association recommends an annual dilated eye examination for people at risk for glaucoma as a preventive eye care measure. Depending on your specific condition, your doctor may recommend more frequent examinations.
What causes glaucoma?
Glaucoma is the leading cause of blindness among Hispanics.
There are many types of glaucoma and many theories about the causes of glaucoma. The exact cause is unknown. Although the disease is usually associated with an increase in the fluid pressure inside the eye, other theories include lack of adequate blood supply to the nerve.
Primary open-angle glaucoma – This is the most common form of glaucoma. One theory is that glaucoma is thought to develop when the eye’s drainage system becomes inefficient over time. This leads to an increased amount of fluid and a gradual buildup of pressure within the eye. Other theories of the cause of the optic nerve damage include poor perfusion, or blood flow, to the optic nerve. Damage to the optic nerve is slow and painless and a large portion of vision can be lost before vision problems are noticed. Other theories also exist.
Angle-closure glaucoma – This type of glaucoma, also called closed-angle glaucoma or narrow angle glaucoma, is a less common form of the disease. It is a medical emergency that can cause vision loss within a day of its onset.
It occurs when the drainage angle in the eye (formed by the cornea and the iris) closes or becomes blocked. Many people who develop this type of glaucoma have a very narrow drainage angle. With age, the lens in the eye becomes larger, pushing the iris forward and narrowing the space between the iris and the cornea. As this angle narrows, the aqueous fluid is blocked from exiting through the drainage system, resulting in a buildup of fluid and an increase in eye pressure.
Angle-closure glaucoma can be chronic (progressing gradually) or acute (appearing suddenly). The acute form occurs when the iris completely blocks the drainage of the aqueous fluid. In people with a narrow drainage angle, if their pupils become dilated, the angle may close and cause a sudden increase in eye pressure. Although an acute attack often affects only one eye, the other eye may be at risk of an attack as well.
Secondary glaucoma – This type of glaucoma occurs as a result of an injury or other eye disease. It may be caused by a variety of medical conditions, medications, physical injuries, and eye abnormalities. Infrequently, eye surgery can be associated with secondary glaucoma.
Normal-tension glaucoma – In this form of glaucoma, eye pressure remains within what is considered to be the “normal” range, but the optic nerve is damaged nevertheless. Why this happens is unknown.
It is possible that people with low-tension glaucoma may have an abnormally sensitive optic nerve or a reduced blood supply to the optic nerve caused by a condition such as atherosclerosis, a hardening of the arteries. Under these circumstances even normal pressure on the optic nerve may be enough to cause damage.
Certain factors can increase the risk for developing glaucoma. They include:
Age – People over age 60 are at increased risk for the disease. For African Americans, however, the increase in risk begins after age 40. The risk of developing glaucoma increases slightly with each year of age.
Race – African Americans are significantly more likely to get glaucoma than are Caucasians, and they are much more likely to suffer permanent vision loss as a result. People of Asian descent are at higher risk of angle-closure glaucoma and those of Japanese descent are more prone to low-tension glaucoma.
Family history of glaucoma – Having a family history of glaucoma increases the risk of developing glaucoma.
Medical conditions – Some studies indicate that diabetes may increases the risk of developing glaucoma, as do high blood pressure and heart disease.
Physical injuries to the eye – Severe trauma, such as being hit in the eye, can result in immediate increased eye pressure and future increases in pressure due to internal damage. Injury can also dislocate the lens, closing the drainage angle, and increasing pressure.
Other eye-related risk factors – Eye anatomy, namely corneal thickness and optic nerve appearance indicate risk for development of glaucoma. Conditions such as retinal detachment, eye tumors, and eye inflammations may also induce glaucoma. Some studies suggest that high amounts of nearsightedness may also be a risk factor for the development of glaucoma.
Corticosteroid use – Using corticosteroids for prolonged periods of time appears to put some people at risk of getting secondary glaucoma.
How is glaucoma diagnosed?
Glaucoma is diagnosed through a comprehensive eye examination. To establish a diagnosis of glaucoma, several factors must be present: Because glaucoma is a progressive disease, meaning it worsens over time, a change in the appearance of the optic nerve, a loss of nerve tissue, and a corresponding loss of vision confirm the diagnosis. Some optic nerves have a suspicious appearance, resembling nerves with glaucoma, but the patients may have no other risk factors or signs of glaucoma. These patients should be closely followed with routine comprehensive exams to monitor for change.
Patient history to determine any symptoms the patient is experiencing and the presence of any general health problems and family history that may be contributing to the problem.
Visual acuity measurements to determine the extent to which vision may be affected.
Tonometry to measure the pressure inside the eye to detect increased risk factors for glaucoma.
Pachymetry to measure corneal thickness. People with thinner corneas are at an increased risk of developing glaucoma.
Visual field testing, also called perimetry, to check if the field of vision has been affected by glaucoma. This test measures your side (peripheral) vision and central vision by either determining the dimmest amount of light that can be detected in various locations of vision, or by determining sensitivity to targets other than light, and comparing it to others of similar age.
Evaluation of the retina of the eye, which may include photographs of the optic nerve, in order to monitor any changes that might occur over time.
Supplemental testing may include gonioscopy, a procedure allowing views of the angle anatomy, the area in the eye where fluid drainage occurs. Serial tonometry may be performed. This is a procedure acquiring several pressure measurements over time, looking for changes in the eye pressure throughout the day. Other tests include using devices to measure nerve fiber thickness, and look for specific areas of the nerve fiber layer for loss of tissue.
How is glaucoma treated?
The treatment of glaucoma is aimed at reducing intraocular pressure. The most common first line treatment of glaucoma is usually prescription eye drops that must be taken regularly. In some cases, systemic medications, laser treatment, or other surgery may be required. While there is no cure as yet for glaucoma, early diagnosis and continuing treatment can preserve eyesight.
Medications – A number of medications are currently available to treat glaucoma. Typically medications are intended to reduce elevated intraocular pressure. One may be prescribed a single medication or a combination of medications. The type of medication may change if it is not providing enough pressure reduction or if the patient is experiencing side-effects from the drops.
Surgery involves either laser treatment, making a drainage flap in the eye, inserting a drainage valve, or destroying the tissue that creates the fluid in the eye. All procedures aim to reduce the pressure inside the eye. Surgery may help lower pressure when medication is not sufficient, however it cannot reverse vision loss.
Laser surgery – Laser trabeculoplasty helps fluid drain out of the eye. A high-energy laser beam is used to stimulate the trabecular meshwork to work more efficiently at fluid drainage. The results may be somewhat temporary, and the procedure may need to be repeated in the future.
Conventional surgery – If eye drops and laser surgery aren’t effective in controlling eye pressure, you may need a filtering procedure called a trabeculectomy. Filtering microsurgery involves creating a drainage flap, allowing fluid to percolate into and later drain into the vascular system.
Drainage implants – Another type of surgery, called drainage valve implant surgery, may be an option for people with uncontrolled glaucoma, secondary glaucoma or for children with glaucoma. A small silicone tube is inserted in the eye to help drain aqueous fluid.
Treatment for acute angle-closure glaucoma
Acute angle-closure glaucoma is a medical emergency. Several medications can be used to reduce eye pressure as quickly as possible. A laser procedure called laser peripheral iridotomy will also likely be performed. In this procedure, a laser beam creates a small hole in the iris to allow aqueous fluid to flow more freely into the front chamber of the eye where it then has access to the meshwork for drainage.
There is no cure for glaucoma. Patients with glaucoma need to continue treatment for the rest of their lives. Because the disease can progress or change silently, compliance with eye medications and eye examinations are essential, as treatment may need to be adjusted periodically.
By keeping eye pressure under control, continued damage to the optic nerve and continued loss of your visual field may slow or stop. The optometrist may focus on lowering the intraocular pressure to a level that is least likely to cause further optic nerve damage. This level is often referred to as the target pressure and will probably be a range rather than a single number. Target pressure differs for each person, depending on the extent of the damage and other factors. Target pressure may change over the course of a lifetime. Newer medications are always being developed to help in the fight against glaucoma.
Early detection, prompt treatment and regular monitoring can help to control glaucoma and therefore reduce the chances of progression vision loss.
An inflammation or infection of the cornea, the clear front cover of the eye.
Keratoconus is a vision disorder that occurs when the normally round cornea (the front part of the eye) becomes thin and irregular (cone) shaped. This abnormal shape prevents the light entering the eye from being focused correctly on the retina and causes distortion of vision.
In its earliest stages, keratoconus causes slight blurring and distortion of vision and increased sensitivity to glare and light. These symptoms usually appear in the late teens or late 20s. Keratoconus may progress for 10-20 years and then slow in its progression. Each eye may be affected differently. As keratoconus progresses, the cornea bulges more and vision may become more distorted. In a small number of cases, the cornea will swell and cause a sudden and significant decrease in vision. The swelling occurs when the strain of the cornea’s protruding cone-like shape causes a tiny crack to develop. The swelling may last for weeks or months as the crack heals and is gradually replaced by scar tissue. If this sudden swelling does occur, your doctor can prescribe eyedrops for temporary relief, but there are no medicines that can prevent the disorder from progressing.
Eyeglasses or soft contact lenses may be used to correct the mild nearsightedness and astigmatism that is caused by the early stages for keratoconus. As the disorder progresses and cornea continues to thin and change shape, rigid gas permeable contact lenses can be prescribed to correct vision adequately. In most cases, this is adequate. The contact lenses must be carefully fitted, and frequent checkups and lens changes may be needed to achieve and maintain good vision.
In a few cases, a corneal transplant is necessary. However, even after a corneal transplant, eyeglasses or contact lenses are often still needed to correct vision.
Lazy Eye (Amblyopia)
The loss or lack of development of clear vision in just one eye. It is not due to eye health problems and eyeglasses or contact lenses can’t fully correct the reduced vision caused by lazy eye. See also Amblyopia.
Learning-related Vision Problems
Vision disorders that interfere with reading and learning.
Age-Related Macular Degeneration (AMD) is the leading cause of severe vision loss in adults over age 50. The Centers for Disease Control and Prevention estimate that 1.8 million people have AMD and another 7.3 million are at substantial risk for vision loss from AMD. Caucasians are at higher risk for developing AMD than other races. Women also develop AMD at an earlier age than men. This eye disease occurs when there are changes to the macula, a small portion of the retina that is located on the inside back layer of the eye. AMD is a loss of central vision that can occur in two forms: “dry” or atrophic and “wet” or exudative.
Most people with macular degeneration have the dry form, for which there is no known treatment. The less common wet form may respond to laser procedures, if diagnosed and treated early.
Some common symptoms are: a gradual loss of ability to see objects clearly, distorted vision, a gradual loss of color vision, and a dark or empty area appearing in the center of vision. If you experience any of these, contact your doctor of optometry immediately for a comprehensive examination. Central vision that is lost to macular degeneration cannot be restored. However, low vision devices, such as telescopic and microscopic lenses, can be prescribed to maximize existing vision.
Researchers have linked eye-friendly nutrients such as lutein/zeaxanthin, vitamin C, vitamin E, and zinc to reducing the risk of certain eye diseases, including macular degeneration. For more information on the importance of good nutrition and eye health, please see the diet and nutrition section.
Migraine with Aura
See Ocular Migraine
Nearsightedness, or myopia, as it is medically termed, is a vision condition in which close objects are seen clearly, but objects farther away appear blurred. Nearsightedness occurs if the eyeball is too long or the cornea, the clear front cover of the eye, has too much curvature. As a result, the light entering the eye isn’t focused correctly and distant objects look blurred.
Nearsightedness is a very common vision condition affecting nearly 30 percent of the U.S. population. Some research supports the theory that nearsightedness is hereditary. There is also growing evidence that it is influenced by the visual stress of too much close work.
Generally, nearsightedness first occurs in school-age children. Because the eye continues to grow during childhood, it typically progresses until about age 20. However, nearsightedness may also develop in adults due to visual stress or health conditions such as diabetes.
A common sign of nearsightedness is difficulty with the clarity of distant objects like a movie or TV screen or the chalkboard in school. A comprehensive optometric examination will include testing for nearsightedness. An optometrist can prescribe eyeglasses or contact lenses that correct nearsightedness by bending the visual images that enter the eyes, focusing the images correctly at the back of the eye. Depending on the amount of nearsightedness, you may only need to wear glasses or contact lenses for certain activities, like watching a movie or driving a car. Or, if you are very nearsighted, they may need to be worn all the time.
Another option for treating nearsightedness is orthokeratology (ortho-k), also known as corneal refractive therapy. It is a non-surgical procedure that involves wearing a series of specially designed rigid contact lenses to gradually reshape the curvature of your cornea. The lenses place pressure on the cornea to flatten it. This changes how light entering the eye is focused.
Laser procedures are also a possible treatment for nearsightedness in adults. They involve reshaping the cornea by removing a small amount of eye tissue. This is accomplished by using a highly focused laser beam on the surface of the eye.
For people with higher levels of nearsightedness, other refractive surgery procedures are now available. These procedures involve implanting a small lens with the desired optical correction directly inside the eye, either just in front of the natural lens (phakic intraocular lens implant) or replacing the natural lens (clear lens extraction with intraocular lens implantation). These procedures are similar to one used for cataract surgery patients, who also have lenses implanted in their eyes (intraocular lens implants).
What causes nearsightedness?
If one or both parents are nearsighted, there is an increased chance their children will be nearsighted.
The exact cause of nearsightedness is unknown, but two factors may be primarily responsible for its development:
There is significant evidence that many people inherit nearsightedness, or at least the tendency to develop nearsightedness. If one or both parents are nearsighted, there is an increased chance their children will be nearsighted.
Even though the tendency to develop nearsightedness may be inherited, its actual development may be affected by how a person uses his or her eyes. Individuals who spend considerable time reading, working at a computer, or doing other intense close visual work may be more likely to develop nearsightedness.
Nearsightedness may also occur due to environmental factors or other health problems:
Some people may experience blurred distance vision only at night. This “night myopia” may be due to the low level of light making it difficult for the eyes to focus properly or the increased pupil size during dark conditions, allowing more peripheral, unfocused light rays to enter the eye.
People who do an excessive amount of near vision work may experience a false or “pseudo” myopia. Their blurred distance vision is caused by over use of the eyes’ focusing mechanism. After long periods of near work, their eyes are unable to refocus to see clearly in the distance. The symptoms are usually temporary and clear distance vision may return after resting the eyes. However, over time constant visual stress may lead to a permanent reduction in distance vision.
Symptoms of nearsightedness may also be a sign of variations in blood sugar levels in persons with diabetes or an early indication of a developing cataract.
An optometrist can evaluate vision and determine the cause of the vision problems.
How is nearsightedness diagnosed?
Testing for nearsightedness may use several procedures in order to measure how the eyes focus light and to determine the power of any optical lenses needed to correct the reduced vision.
A phoropter and retinoscope are often used to determine the lenses that allow the clearest vision during a comprehensive eye exam.
As part of the testing, letters on a distance chart are identified. This test measures visual acuity, which is written as a fraction such as 20/40. The top number of the fraction is the standard distance at which testing is performed, twenty feet. The bottom number is the smallest letter size read. A person with 20/40 visual acuity would have to get within 20 feet to identify a letter that could be seen clearly at forty feet in a “normal” eye. Normal distance visual acuity is 20/20, although many people have 20/15 (better) vision.
Using an instrument called a phoropter, an optometrist places a series of lenses in front of your eyes and measures how they focus light using a hand held lighted instrument called a retinoscope. The doctor may choose to use an automated instrument that automatically evaluates the focusing power of the eye. The power is then refined by patient’s responses to determine the lenses that allow the clearest vision.
This testing may be done without the use of eye drops to determine how the eyes respond under normal seeing conditions. In some cases, such as for patients who can’t respond verbally, or when some of the eye’s focusing power may be hidden, eye drops may be used. They temporarily keep the eyes from changing focus while testing is performed.
Using the information obtained from these tests, along with the results of other tests of eye focusing and eye teaming, your optometrist can determine if you have nearsightedness. He or she will also determine the power of any lens correction needed to provide clear vision. Once testing is complete, your optometrist can discuss options for treatment.
How is nearsightedness treated?
Persons with nearsightedness have several options available to regain clear distance vision. They include:
laser and other refractive surgery procedures
vision therapy for persons with stress-related nearsightedness.
Eyeglasses are the primary choice of correction for persons with nearsightedness. Generally, a single vision lens is prescribed to provide clear vision at all distances. However, for patients over about age 40, or children and adults whose nearsightedness is due to the stress of near vision work, a bifocal or progressive addition lens may be needed. These multifocal lenses provide different powers or strengths throughout the lens to allow for clear vision in the distance and also clear vision up close.
Eyeglasses are frequently used to correct myopia.
A large selection of lens types and frame designs are now available for patients of all ages. Eye glasses are no longer just a medical device that provides needed vision correction, but can also be a fashion statement. They are available in a wide variety of sizes, shapes, colors and materials that not only correct for vision problems but also may enhance appearance.
For some individuals, contact lenses can offer better vision than eyeglasses. They may provide clearer vision and a wider field of view. However, since contact lenses are worn directly on the eyes, they require regular cleaning and care to safeguard eye health.
Orthokeratology (Ortho-k), also known as corneal refractive therapy, involves the fitting of a series of rigid contact lenses to reshape the cornea, the front outer surface of the eye. The contact lenses are worn daily for limited periods, such as overnight, and then removed. Persons with moderate amounts of nearsightedness may be able to temporarily obtain clear vision for most of their daily activities.
Nearsightedness can also be corrected by reshaping the cornea using a laser beam of light. Two commonly used procedures are photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK).
In PRK, a laser is used to remove a thin layer of tissue from the surface of the cornea in order to change its shape and refocus light entering the eye. There is a limit to how much tissue can safely be removed and therefore the amount of nearsightedness that can be corrected.
LASIK does not remove tissue from the surface of the cornea, but from its inner layers. To do this, a section of the outer corneal surface is cut and folded back to expose the inner tissue. Then a laser is used to remove the precise amount of corneal tissue needed to reshape the eye, and then the flap of outer tissue is placed back in position to heal. The amount of nearsightedness that LASIK can correct is limited by the amount of corneal tissue that can be removed in a safe manner.
People who are highly nearsighted or whose corneas are too thin to allow the use of laser procedures now have another option. They may be able to have their nearsightedness surgically corrected by implanting small lenses in their eyes. These intraocular lenses look like small contact lenses and they provide the needed optical correction directly inside the eye.
Vision therapy is an option for people whose blurred distance vision is caused by a spasm of the muscles which control eye focusing. Various eye exercises can be used to improve poor eye focusing ability and regain clear distance vision.
People with nearsightedness have a variety of options to correct their vision problem. In consultation with your optometrist, you can select the treatment that best meets you visual and lifestyle needs.
A vision condition in which you can see close objects clearly, but objects farther away are blurred.
Nystagmus is a vision condition in which the eyes make repetitive, uncontrolled movements, often resulting in reduced vision. These involuntary eye movements can occur from side to side, up and down, or in a circular pattern. As a result, both eyes are unable to hold steady on objects being viewed. Nystagmus may be accompanied by unusual head positions and head nodding in an attempt to compensate for the condition.
Nystagmus can be inherited and appear in early childhood or develop later in life due to an accident or illness. Generally, nystagmus is a symptom of some other underlying eye or medical problem. However, the exact cause is often unknown.
Persons with nystagmus may experience reduced visual acuity. They may also have problems with depth perception that can affect their balance and coordination. Nystagmus can be aggravated by fatigue and stress.
Most individuals with nystagmus can reduce the severity of their uncontrolled eye movements and improve vision by positioning their eyes to look to one side. This is called the “null point” where the least amount of nystagmus is evident. To accomplish this they may need to adopt a specific head posture to make the best use of their vision.
The forms of nystagmus include:
Congenital – most often develops by 2 to 3 months of age. The eyes tend to move in a horizontal swinging fashion. It is often associated with other conditions such as albinism, congenital absence of the iris (the colored part of the eye), underdeveloped optic nerves, and congenital cataract.
Spasmus nutans – usually occurs between 6 months and 3 years of age and resolves spontaneously between 2 and 8 years of age. Children with this form of nystagmus often display head nodding and a head tilt. Their eyes may move in any direction. This type of nystagmus usually does not require treatment.
Acquired – develops later in childhood or adulthood. The cause is often unknown, but it may be due to central nervous system and metabolic disorders or alcohol and drug toxicity.
Nystagmus can be further classified by the type of motion the eyes make:
Pendular nystagmus – the speed of movement of the eyes is in same in both directions.
Jerk nystagmus – the eyes move slowly in one direction and then quickly “jerk” back in the other direction.
What causes nystagmus?
Nystagmus results from the instability or impairment of the system responsible for controlling eye movements. When nystagmus develops in early childhood, it can be caused by a problem with the visual pathway from the eye to the brain. Often the child has no other eye or medical problem. Acquired nystagmus, which occurs later in life, can be the symptom of another condition such as stroke, multiple sclerosis or a blow to the head.
Other causes of nystagmus include:
Lack of development of normal eye movement control early in life
Very high refractive error, e.g. nearsightedness (myopia) or astigmatism
Inflammation of the inner ear
Medications such as anti-epilepsy drugs
Central nervous system diseases
How is nystagmus diagnosed?
Nystagmus can be diagnosed through a comprehensive eye exam. Testing for nystagmus, with special emphasis on how the eyes move, may include:
Patient history to determine any symptoms the patient is experiencing and the presence of any general health problems, medications taken, or environmental factors that may be contributing to the symptoms.
Visual acuity measurements to assess the extent to which vision may be affected.
A refraction to determine the appropriate lens power needed to compensate for any refractive error (nearsightedness, farsightedness, or astigmatism).
Testing how the eyes focus, move and work together. In order to obtain a clear, single image of what is being viewed, the eyes must effectively change focus, move and work in unison. This testing will look for problems that affect the control of eye movements or make it difficult to use both eyes together.
Since nystagmus is often the result of other underlying health problems, your optometrist may refer you to your primary care physician or other medical specialist for further testing.
Using the information obtained from testing, your optometrist can determine if you have nystagmus and advise you on treatment options.
How is nystagmus treated?
Nystagmus can not be cured. While eyeglasses and contact lenses do not correct nystagmus, they can help to correct other vision problems such as nearsightedness, farsightedness or astigmatism.
Some types of nystagmus improve throughout childhood. In addition, vision may be enhanced with prisms and special glasses. The use of large-print books, magnifying devices and increased lighting can also be helpful.
Rarely, surgery is performed to alter the position of the muscles, which move the eyes. While it does not cure nystagmus, it may reduce the amount of head turn needed for best vision.
Treatment for other underlying eye or medical problems may help to improve or reduce nystagmus.
The abnormal response of sensitive eyes to contact with allergens and other irritating substances.
Ocular hypertension is an increase in the pressure in your eyes that is above the range considered normal with no detectable changes in vision or damage to the structure of your eyes. The term is used to distinguish people with elevated pressure from those with glaucoma, a serious eye disease that causes damage to the optic nerve and vision loss.
Ocular hypertension can occur in people of all ages, but it occurs more frequently in African Americans, those over age 40 and those with family histories of ocular hypertension and/or glaucoma. It is also more common in those who are very nearsighted or who have diabetes.
Ocular hypertension has no noticeable signs or symptoms. Your doctor of optometry can check the pressure in your eyes with an instrument called a tonometer and can examine the inner structures of your eyes to assess your overall eye health.
Not all people with ocular hypertension will develop glaucoma. However, there is an increased risk of glaucoma among those with ocular hypertension, so regular comprehensive optometric examinations are essential to your overall eye health.
There is no cure for ocular hypertension, however, careful monitoring and treatment, when indicated, can decrease the risk of damage to your eyes.
A type of severe headache accompanied by various visual symptoms.
An abnormal growth of tissue on the conjunctiva, the clear membrane that covers the white of the eye.
Presbyopia is a vision condition in which the crystalline lens of your eye loses its flexibility, which makes it difficult for you to focus on close objects.
Presbyopia may seem to occur suddenly, but the actual loss of flexibility takes place over a number of years. Presbyopia usually becomes noticeable in the early to mid-40s. Presbyopia is a natural part of the aging process of the eye. It is not a disease, and it cannot be prevented.
Some signs of presbyopia include the tendency to hold reading materials at arm’s length, blurred vision at normal reading distance and eye fatigue along with headaches when doing close work. A comprehensive optometric examination will include testing for presbyopia.
To help you compensate for presbyopia, your optometrist can prescribe reading glasses, bifocals, trifocals or contact lenses. Because presbyopia can complicate other common vision conditions like nearsightedness, farsightedness and astigmatism, your optometrist will determine the specific lenses to allow you to see clearly and comfortably. You may only need to wear your glasses for close work like reading, but you may find that wearing them all the time is more convenient and beneficial for your vision needs.
Because the effects of presbyopia continue to change the ability of the crystalline lens to focus properly, periodic changes in your eyewear may be necessary to maintain clear and comfortable vision.
An abnormal growth of tissue on the conjuctiva, the clear membrane that covers the white of the eye, and the adjacent cornea, the clear front surface of the eye.
A drooping of the upper eyelid.
A tearing or separation of the retina, the light sensitive lining at the back of the eye, from the underlying tissue.
The first sign of retinitis pigmentosa is often night blindness followed by a slow loss of side vision.
Retinitis pigmentosa (RP) is a group of inherited diseases that damage the light-sensitive rods and cones located in the retina, the back part of our eyes. Rods, which provide side (peripheral) and night vision are affected more than the cones that provide color and clear central vision.
Signs of RP usually appear during childhood or adolescence. The first sign is often night blindness followed by a slow loss of side vision. Over the years, the disease will cause further loss of side vision. As the disease develops, people with RP may often bump into chairs and other objects as side vision worsens and they only see in one direction – straight ahead. They see as if they are in a tunnel (thus the term tunnel vision).
Fortunately, most cases of retinitis pigmentosa take a long time to develop and vision loss is gradual. It may take many years for loss of vision to be severe.
Currently, there is no cure for RP, but there is research that indicates that vitamin A and lutein may slow the rate at which the disease progresses. Your doctor of optometry can give you more specific information on nutritional supplements that may help you.
Also, there are many new low vision aids, including telescopic and magnifying lenses, night vision scopes as well as other adaptive devices, that are available that help people maximize the vision that they have remaining. An optometrist, experienced in low vision rehabilitation, can provide these devices as well as advice about other training and assistance to help people remain independent and productive.
Becuase it is an inherited disease, research into genetics may one day provide a prevention or cure for those who have RP.
Every parent dreads to hear the word “cancer,” but cancer has a high prevalence in the United States. Early detection of cancer can greatly reduce the severity of the illness and increase life expectancy.
Optometrists diagnose, refer, and comanage cancers that involve the eye area. The most common cancer involving the eye in young children is retinoblastoma. In the United States, this fast-growing cancer occurs in 1 in every 20,000 children, making it the tenth most common pediatric cancer.
There are 2 forms of retinoblastoma—hereditary and sporadic. Although sporadic retinoblastoma occurs more frequently, families with a history of hereditary retinoblastoma should be assessed.
Adapted from Hoppe E, Frankel R. Optometrists as key providers in the prevention and early detection of malignancies. Optometry (2006) 77, 397-404
Crossed eyes, or strabismus as it is medically termed, is a condition in which both eyes do not look at the same place at the same time. It occurs when an eye turns in, out, up or down and is usually caused by poor eye muscle control or a high amount of farsightedness.
There are six muscles attached to each eye that control how it moves. The muscles receive signals from the brain that direct their movements. Normally, the eyes work together so they both point at the same place. When problems develop with eye movement control, an eye may turn in, out, up or down. The eye turning may be evident all the time or may appear only at certain times such as when the person is tired, ill, or has done a lot of reading or close work. In some cases, the same eye may turn each time, while in other cases, the eyes may alternate turning.
Maintaining proper eye alignment is important to avoid seeing double, for good depth perception, and to prevent the development of poor vision in the turned eye. When the eyes are misaligned, the brain receives two different images. At first, this may create double vision and confusion, but over time the brain will learn to ignore the image from the turned eye. If the eye turning becomes constant and is not treated, it can lead to permanent reduction of vision in one eye, a condition called amblyopia or lazy eye.
Some babies’ eyes may appear to be misaligned, but are actually both aiming at the same object. This is a condition called pseudostrabismus or false strabismus. The appearance of crossed eyes may be due to extra skin that covers the inner corner of the eyes, or a wide bridge of the nose. Usually, this will change as the child’s face begins to grow.
Strabismus usually develops in infants and young children, most often by age 3, but older children and adults can also develop the condition. There is a common misconception that a child with strabismus will outgrow the condition. However, this is not true. In fact, strabismus may get worse without treatment. Any child older than four months whose eyes do not appear to be straight all the time should be examined.
Strabismus is classified by the direction the eye turns:
Inward turning is called esotropia
Outward turning is called exotropia
Upward turning is called hypertropia
Downward turning is called hypotropia.
Other classifications of strabismus include:
The frequency with which it occurs – either constant or intermittent
Whether it always involves the same eye – unilateral
If the turning eye is sometimes the right eye and other times the left eye – alternating.
Treatment for strabismus may include eyeglasses, prisms, vision therapy, or eye muscle surgery. If detected and treated early, strabismus can often be corrected with excellent results.[
What causes strabismus?
Strabismus can be caused by problems with the eye muscles, the nerves that transmit information to the muscles, or the control center in the brain that directs eye movements. It can also develop due to other general health conditions or eye injuries.
Risk factors for developing strabismus include:
Family history – individuals with parents or siblings who have strabismus are more likely to develop it.
Refractive error – people who have a significant amount of uncorrected farsightedness (hyperopia) may develop strabismus because of the additional amount of eye focusing required to keep objects clear.
Medical conditions – people with conditions such as Down syndrome and cerebral palsy or who have suffered a stroke or head injury are at a higher risk for developing strabismus.
Although there are many types of strabismus that can develop in children or adults, the two most common forms are accommodative esotropia and intermittent exotropia.
Accommodative esotropia often occurs because of uncorrected farsightedness (hyperopia). Because the eye’s focusing system is linked to the system that controls where the eyes point, the extra focusing effort needed to keep images clear in farsightedness may cause the eyes to turn inward. Signs and symptoms of accommodative esotropia may include seeing double, closing or covering one eye when doing close work, and tilting or turning of the head.
Intermittent exotropia may develop due to an inability to coordinate both eyes together. The eyes may have a tendency to point beyond the object being viewed. People with intermittent exotropia may experience headaches, difficulty reading, and eye strain. They also may have a tendency to close one eye when viewing at distance or in bright sunlight.
How is strabismus diagnosed?
Strabismus is diagnosed through a comprehensive eye exam. Testing for strabismus, with special emphasis on how the eyes focus and move, may include:
Patient History – A patient history is obtained to determine any symptoms the patient is experiencing or the parent is observing, and to note the presence of any general health problems, medications taken, or environmental factors that may be contributing to the symptoms.
Visual Acuity – Visual acuity measurements are taken to assess the extent to which vision may be affected. As part of the testing, you will be asked to read letters on distance and near reading charts. This test measures visual acuity, which is written as a fraction such as 20/40. When testing distance vision, the top number is the standard distance at which testing is done, twenty feet. The bottom number is the smallest letter size you were able to read at the twenty foot distance. A person with 20/40 visual acuity would have to get within 20 feet of a letter that should be seen at forty feet in order to see it clearly. “Normal” distance visual acuity is 20/20.
Refraction – A refraction is conducted to determine the appropriate lens power needed to compensate for any refractive error (nearsightedness, farsightedness, or astigmatism). Using an instrument called a phoropter, your optometrist places a series of lenses in front of your eyes and measures how they focus light using a hand held lighted instrument called a retinoscope. Or the doctor may choose to use an automated instrument that automatically evaluates the refractive power of the eye. The power is then refined by the patient’s responses to determine the lenses that allow the clearest vision.
Alignment and Focusing Testing – How well your eyes focus, move and work together needs to be assessed. In order to obtain a clear, single image of what is being viewed, the eyes must effectively change focus, move and work in unison. This testing will look for problems that keep your eyes from focusing effectively or make it difficult to use both eyes together.
Examination of eye health – The structures of the eye are observed to rule out any eye disease that may be contributing to strabismus. The health of the external and internal parts of the eye will be assessed using various testing procedures.
This testing may be done without the use of eye drops to determine how the eyes respond under normal seeing conditions. In some cases, such as for patients who can’t respond verbally or when some of the eyes focusing power may be hidden, eye drops may be used. They temporarily keep the eyes from changing focus while testing is done.
Using the information obtained from these tests, along with results of other tests, your optometrist can determine if you have strabismus. Once testing is complete, your optometrist can discuss options for treatment.
How is strabismus treated?
People with strabismus have several treatment options available to improve eye alignment and coordination. They include:
eyeglasses or contact lenses
eye muscle surgery
Eyeglasses or contact lenses may be prescribed for patients with uncorrected farsightedness. This may be the only treatment needed for some patients with accommodative esotropia. Once the farsightedness is corrected, the eyes require less focusing effort and may remain straight.
Prism lenses are special lenses that have a prescription for prism power in them. The prisms alter the light entering the eye and assist in reducing the amount of turning the eye has to do to look at objects. Sometimes the prisms are able to fully compensate for and eliminate the eye turning.
Vision therapy is a structured program of visual activities prescribed to improve eye coordination and eye focusing abilities. Vision therapy trains the eyes and brain to work together more effectively. These eye exercises help remediate deficiencies in eye movement, eye focusing and eye teaming and reinforce the eye-brain connection. Treatment may include office-based as well as home training procedures.
Eye muscle surgery can change the length or position of the muscles around the eye in an attempt to better align the eyes. Eye muscle surgery may be able to physically align the eyes so they appear straight. Often a program of vision therapy may also be needed to develop a functional improvement in eye coordination and to keep the eyes from reverting back to their previous condition of misalignment.
Also See Crossed Eyes.
An infection of an oil gland in the eyelid.
An accumulation of blood underneath the conjunctiva, the clear membrane covering the white part of the eye.
Anterior uveitis is an inflammation of the middle layer of the eye, which includes the iris (colored part of the eye) and adjacent tissue, known as the ciliary body. If untreated, it can cause permanent damage and loss of vision from the development of glaucoma, cataract or retinal edema. It usually responds well to treatment; however, there may be a tendency for the condition to recur. Treatment usually includes prescription eye drops, which dilate the pupils, in combination with anti-inflammatory drugs. Treatment usually takes several days, or up to several weeks, in some cases.
Anterior uveitis can occur as a result of trauma to the eye, such as a blow or foreign body penetrating the eye. It can also be a complication of other eye disease, or it may be associated with general health problems such as rheumatoid arthritis, rubella and mumps. In most cases, there is no obvious underlying cause.
Signs/symptoms may include a red, sore and inflamed eye, blurring of vision, sensitivity to light and a small pupil. Becuase the symptoms of anterior uveitis are similar to those of other eye diseases, your optometrist will carefully examine the inside of your eye, under bright light and high magnification, to determine the presence and severity of the condition. Your optometrist may also perform or arrange for other diagnostic tests to help pinpoint the cause.
Some symptoms of Anterior uveitis include a red, sore and inflamed eye, and a small pupil.