Cataracts are usually the result of the normal aging process. A cataract is simply the clouding of the lens. When the lens becomes cloudy, the flow of light is distorted and the picture formed on the retina becomes dim or blurry.
Many factors can increase the rate at which a cataract will form. Some of the major ones include family history, injury, past eye surgery, certain medications, diabetes, poor nutrition, and exposure to ultraviolet radiation from the sun.
Although many of these factors can be minimized, there is little you can do to stop the aging process. Just as hair turns gray with time, the lens of the eye turns cloudy with age. Younger people can develop early cataracts, similar to the premature graying of hair, although cataracts typically occur after the age of 45.