A cataract is a clouding of the lens in the eye leading to a decrease in vision. It can affect one or both eyes. Often it develops slowly. Symptoms may include faded colors, blurry vision, halos around light, trouble with bright lights, and trouble seeing at night. This may result in trouble driving, reading, or recognizing faces.

The only treatment for cataracts is surgery. The intervention consists of removing the clouded lens and replacing it with an artificial lens (intra-ocular implant), which is placed in the envelope of the lens that is left in place during the surgery. This surgery is usually done with local or topical anesthesia and takes approximately 10 minutes. It is painless and sight returns quickly, barring any abnormalities in the other structures of the eye.