A cataract is a progressive clouding of the eye's natural lens (the part of the eye responsible for focusing light and producing sharp images). The most common signs of cataract development are blurred or fuzzy vision and sensitivity to light. These symptoms often show themselves as a difficulty in driving, particularly at night. For some people, cataracts make reading difficult, especially when reading fine print.

Cataracts can be diagnosed only by a thorough medical eye exam by an ophthalmologist. There is no medical treatment that will prevent cataracts or reverse them once they develop. The only treatment for cataracts is their surgical removal.