What Is a Cataract?

A cataract is a clouding of the lens in the eye.  By age 80, more than half of all Americans either have a cataract or have had cataract surgery.  The lens is a clear part of the eye that helps to focus an image on the retina.  The lens must be clear for the retina to receive a sharp image.  If the lens is cloudy from a cataract, the image will be blurred.

The lens is made of mostly water and protein.  The protein is arranged in a precise way that keeps the lens clear and lets light pass through it.  As we age, some of the protein may clump together and start to cloud a small area of the lens.  This is a cataract.  Over time, the cataract may grow larger and cloud more of the lens, making it harder to see.

A cataract needs to be removed only when vision loss interferes with everyday activities, such as driving, reading or watching TV.  You and your doctor can make this decision together.

Source:  National Eye Institute