Fact Sheet:

Cataract Surgery

	A cataract is a clouding of the eye’s lens that can cause vision problems. The lens is the part of the eye that helps focus light on the retina, the eye’s light-sensitive layer that sends visual signals to the brain. In a normal eye, light passes through the lens and gets focused on the retina. To help produce a sharp image, the lens must remain clear.
In its early stages, a cataract may not cause a vision problem. The cloudiness may affect only a small part of the lens. Over time, the cataract may grow larger and cloud more of the lens, making it harder to see. Scientists think there may be several causes, including aging, smoking, diabetes and excessive exposure to sunlight. Cataracts can also develop soon after an eye injury, or even years later.
		The most common type of cataract is related to aging. More than half of all Americans age 65 and older have a cataract. Cataracts affect men and women equally, as well as all races and ethnic groups.
In the early stages of cataracts, stronger lighting and eyeglasses may lessen vision problems caused by the clouding of the lenses. At a certain point, however, surgery may be needed to improve vision. This treatment involves removing the cloudy lens and replacing it with an artificial lens.
Today, cataract surgery is safe and effective; each year more than two-and-a-half million cataracts are removed in the United States, and at least six million more are removed outside the United States.

Source: National Eye Institute, National Institutes of Health