A cataract is a clouding of all or part of the normally clear lens within your eye, which results in blurred or distorted vision. Cataracts are most often found in persons over age 55, but they are also occasionally found in younger people.

No one knows exactly what causes cataracts, but it is known that a chemical change occurs within your eye to cause the lens to become cloudy. This may be due to advancing age, heredity or an injury or disease. Excessive exposure to ultraviolet radiation in sunlight, cigarette smoking or the use of certain medications are also risk factors for the development of cataracts.

Although cataracts develop without pain or discomfort, there are some indications that a cataract may be forming. These include blurred or hazy vision, the appearance of spots in front of the eyes, increased sensitivity to glare or the feeling of having a film over the eyes. A temporary improvement in near vision may also indicate formation of a cataract.

Currently, there is no proven method to prevent cataracts from forming. During a comprehensive eye examination, your optometrist can diagnose a cataract and monitor its development and prescribe changes in eyeglasses or contact lenses to maintain good vision.

If your cataract develops to the point that it affects your daily activities, your optometrist can refer you to an eye surgeon who may recommend surgery. During the surgery, the eye's natural lens is removed and usually replaced with a plastic artificial lens. After surgery, you can return to your optometrist for continuing care.