A cataract is an eye disorder in which the lens, which is usually crystal clear, becomes clouded, making it difficult for the patient to see. Cataracts are common eye disorders, usually associated with aging. Most cataracts need not be taken seriously, but ophthalmologists and eye care specialists usually recommend correction through surgical procedures, which will improve vision. However, these surgical procedures must be undergone when loss of vision owing to cataract makes it difficult for the patient to do his/her daily work.
What is a Cataract?
A cataract, as previously mentioned, is an eye disorder in which the lens becomes cloudy and opaque, making it difficult for the patient to see.
The lens of the normal eye is crystal clear and its normal function is to focus light rays that enter the eye on the retina, a photosensitive tissue rich in rods and cones that is located at the back portion of the eye. If the retina is to receive a clear picture, the lens ought to be crystal clear. When light rays focus on the retina, a chemical reaction takes place and an electrical response is formed, which is sent to the brain through the optic nerve. The brain, which receives this message, makes sense of the object seen by the eye.
If the lens is normal, light easily passes through and the image that forms on the retina is sharp and clear. If the lens is cloudy and opaque, the image is blurred, which means that the patient cannot see properly.
The ageing process is responsible for most cataracts and people can develop cataracts in one or both eyes. A person who has developed a cataract in one eye usually ends up developing a cataract in the other eye too. Since a cataract is not an infectious disease, it cannot spread from one eye to the other or from one person to the other. Cataracts are painless and do not cause symptoms such as itching, irritation, or red eyes.
Loss of vision owing to cataracts is not permanent and a simple surgical procedure can easily restore vision in most cases. Simultaneously, the fact remains that the common causes of blindness in aged people are cataracts.
A cataract can be categorized on the basis of its location, intensity of clouding, or the factors causing it.
The nucleus is the central portion of the lens and it is enclosed with the capsule. The part of the lens between the nucleus and the capsule is called the cortex. The lens can get cloudy in the nucleus, cortex, or capsule; accordingly, the cataract is called nuclear cataract, cortical cataract, or subcapsular cataract. However, multiple portions of the lens can get cloudy and it isn’t a rule that only a certain part of the lens must get cloudy.
Depending on the intensity of clouding of the lens, a cataract can be severe, moderate, or mild. If the lens has become completely opaque, the condition is called mature cataract.
Here is a list of the various causes of cataract:
• Eye injury
• Surgical procedures to correct other eye disorders
• Excessive exposure to X-ray, infrared rays, and UV rays
• Inflammation of certain parts of the eye
• Genetic disorders such as Wilson’s disease, Down syndrome, myotonic dystrophy, homocystinuria, glactosemia, and others
• Medication such as prednisone and other oral corticosteroids
• Skin disorders
A cataract can also be congenital, in which case a baby is born with a cataract.
A cataract, which is in its early stages, can be corrected by wearing glasses or using magnifying lens.
In most cases, surgery is not required. Usually, ophthalmologists suggest surgery when patients are no longer able to do their daily work such as reading, driving, viewing TV, and so on. In some cases, ophthalmologists may suggest surgery if the cataract prevents detection and diagnosis of another eye disorder.
Since a cataract has no painful symptoms and doesn’t cause any harm to the eye, one can opt for surgery only when it is absolutely necessary. Modern surgical procedures include the removal of the natural lens and its replacement with an artificial lens, which is purchased well in advance.