Ninety percent of patients can achieve a corrected vision of 20/40 or better as a result of cataract surgery. During the procedure the cataract is removed and, in most cases, replaced with an artificial lens called an intraocular lens implant (IOL). The whole procedure takes 30 to 45 minutes. Directly after surgery the patient’s vision will usually worsen before improving significantly within a few days. The procedure is recommended for anyone whose vision is impaired as a result of cataracts but it is not recommended for those with other eye diseases.