Cataract surgery is one of the safest and most successful procedures performed today. It is the most commonly performed surgery in the United States, with over 2 million Americans having the procedure every year. Once the clouded natural lens is removed, a clear intraocular lens (IOL) is implanted. The procedure is performed on an outpatient basis. Most people are surprised to find out just how easy and pain-free cataract surgery is. It usually takes 20 to 30 minutes or less and most patients have improved vision soon after surgery, but sight may continue to improve for several days or weeks.