The surgery is performed under local anesthesia. Monitoring by attending anesthesiologists is standard; sedatives can be administered as needed. Worldwide, cataract surgery is one of the most common procedures in ophthalmology. The clouded lens is fragmented using ultrasound and replaced with an artificial lens. This lens usually remains in the eye for life. In some cases, the use of a specialized lens can be beneficial, for example, astigmatism can be corrected with a toric intraocular lens.