A cataract is a clouding of the lens in the eye which leads to a decrease in vision. It is the most common cause of blindness and is conventionally treated with surgery. Age is the most common cause but there are a variety of other causes. As we age, yellow-brown pigment is deposited within the lens and this, together with disruption of the normal architecture of the lens fibers, leads to reduced transmission of light, which in turn leads to visual problems. This process is accelerated by diseases such as diabetes and hypertension.
By age 80, more than half of all Americans either have a cataract or have had cataract surgery. Cataracts may be partial or complete, stationary or progressive, or hard or soft. The main types of age-related cataracts are nuclear sclerosis, cortical, and posterior subcapsular.
People with cataracts commonly experience difficulty appreciating colors and changes in contrast, driving, reading, recognizing faces, and experience problems coping with glare from bright lights.
Although most cataracts are related to aging, there are other types of cataracts
1. Secondary cataract. Cataracts can form after surgery for other eye problems, such as glaucoma. Cataracts also can develop in people who have other health problems, such as diabetes. Cataracts are sometimes linked to steroid use.
2. Traumatic cataract. Cataracts can develop after an eye injury, sometimes years later.
3. Congenital cataract. Some babies are born with cataracts or develop them in childhood, often in both eyes. These cataracts may be so small that they do not affect vision. If they do, the lenses may need to be removed.
4. Radiation cataract. Cataracts can develop after exposure to some types of radiation. The severity of cataract formation, assuming that no other eye disease is present, is judged primarily by a visual acuity test. The appropriateness of surgery depends on a patient's particular functional and visual needs and other risk factors, all of which may vary widely.
Wearing sunglasses and a hat with a brim to block ultraviolet sunlight may help to delay cataracts. If you smoke, stop. Researchers also believe good nutrition can help reduce the risk of age-related cataract. They recommend eating green leafy vegetables, fruit, and other foods with antioxidants.
If you are age 60 or older, you should have a comprehensive dilated eye exam at least once every two years. In addition to cataracts, your eye care professional can check for signs of age-related macular degeneration, glaucoma, and other vision disorders. Early treatment for many eye diseases may save your sight.