A cataract is a clouding of the normally clear lens of the eye which leads to a decrease in vision. Cataracts often develop slowly over the course of years and can affect one or both eyes.
Cataract surgery is also known as lens replacement surgery. In this procedure, the lens inside the eye that has become cloudy (natural lens) is removed and replaced with an artificial lens (intraocular lens or IOL) to restore clear vision.
If a patient suffers from cataracts in both eyes, he/she probably needs two surgeries, with an interval of at least two weeks.