Cataract surgery is a procedure to remove the lens of your eye and, in most cases, replace it with an artificial lens. Cataract surgery is used to treat the clouding of the normally clear lens of your eye (cataract).Cataract surgery is performed by an eye doctor (ophthalmologist) on an outpatient basis, which means you don't have to stay in the hospital after the surgery. Cataract surgery is very common and is generally a safe procedure.