Over 1 million cataract surgeries are performed in the United States each year. Two types of surgery are used: phacoemulsification and extracapsular surgery. In both types, after the natural lens has been removed, it is replaced by an artificial one, called an intraocular lens. In about 90 percent of cases, people who have surgery to remove cataracts have better vision afterward. Cataract surgery usually takes less than an hour, and many patients choose to remain awake for the procedure.