Vision Information - What are Cataracts?
Clouding of the eye's natural lens is called cataracts, which are a leading cause of blindness in the world today. Although composed mostly of water, proteins also are arranged on the lens in a very precise way allowing light to pass through while keeping it clear. Over time the proteins clump together causing cloudy spots on the lens and, if left untreated, can cover the entire lens resulting in severe vision disruption or blindness.
Cataracts fall into three categories:
Cortical cataract which forms in the cortex of the lens, growing gradually from outside to inside, and is a form of cataract common in diabetics.
Subcapsular cataract which forms at the back of the lens and is common in people with diabetes or retinitis pigmentosa.
Nuclear cataract is the most common cataract and forms in the center of the lens.
Though exact causes of cataracts are unknown, scientists have identified numerous factors that might indicate cataract formation.
Some studies suggest that cataracts might be caused, partially at least, by exposure to ultraviolet (UV) light rays. As it is always important to reduce the amount of UV light your eyes are exposed to, wearing sunglasses outdoors is recommended by eye care practitioners.
As noted above in two of the cataracts types, people with diabetes reveal a tendency to develop cataracts. People using steroids, diuretics and other forms of medication show a similar tendency, but it is not yet clear if it is the medications that contribute to cataract formation or the illness itself that is the cause.
Other possible contributing factors to cataract formation include air pollution, smoking, and heavy alcohol consumption.
In addition to protecting your eyes from harmful UV radiation, doctors suggest that a diet high in vitamins A, C, E and other antioxidants may help to prevent cataract formation.
In the early stages, cataracts may not cause significant symptoms, but eventually you might experience slightly blurred vision or note that some forms of light seem too bright such as sunlight or oncoming automobile headlights.
While a subcapsular cataract may not produce any symptoms until the advanced stages of its development, nuclear cataracts might improve vision for a short period. This is called "second sight", but soon diminishes as the cataract grows.
If you suspect you are developing a cataract, please consult your eye doctor.
While cataracts are in the early stages of formation, eyesight can generally be improved by simply wearing eyeglasses or utilizing other visual aids. But once cataracts have reached the point where they become a serious visual impairment, it is likely that surgery will have to be considered.
Today, cataract surgery is a simple and relatively painless procedure. More than three million people undergo cataract surgery in the United States every year, making it the most common surgery in the country.
The surgery usually involves complete removal of the affected lens from the eye and replacing it with an artificial intraocular lens (IOL) made of plastic. Ongoing advancements in intraocular lenses continue to make cataract surgeries less complex and more efficient.