A cataract is clouding or yellowing in the lens of the eye. The lens is a structure on the inside of the eye that allows people to focus. A cataract may result in fuzzy or blurry vision. If this occurs, the lens can be removed surgically. Usually, the lens is replaced with a firm, plastic lens implant. Other choices include the use of contact lenses or thick cataract eyeglasses to help take over the job of the missing lens.

While all three choices sharpen vision after surgery, cataract eyeglasses greatly enlarge images. This changes depth perception, which can lead to problems walking or doing many tasks. Some people find contact lenses irritating to the eyes or have trouble putting them in because of poor vision. These problems have made lens implants during cataract surgery the standard choice in most cases.

Who is a candidate for the procedure?

People who find day-to-day living, hobbies or work difficult because of cataracts that reduce vision are good candidates for this procedure. If a person's sight is only slightly affected, cataract surgery is often delayed until poor vision justifies the small risk of the operation. The type of lifestyle a person leads may also affect the timing of the surgery.

How is the procedure performed?

The surgery does not require an overnight stay in the hospital. First, an anesthetic is used to numb the eye. Many people are also given drugs injected into a vein to help them relax. A small cut is made on one edge of the cornea. This is the tough, clear cover over the front of the eye. The lens is then broken into small pieces manually or crushed into tiny pieces using special sound waves. These pieces are then removed from the eye.

If a lens implant is chosen, it is usually placed in the same area as the original lens. Occasionally, the lens implant is placed closer to the front of the eye than the original lens. Often, no stitches are needed to close the incision.