As doctors find more and better ways to correct visual disorders, new surgical procedures will gradually come into common use. RK (R-K), considered revolutionary when first introduced, is now just one of several methods to correct refractive errors; it's joined by PRK (P-R-K), which reshapes the cornea with a laser, and ALK, or automated lamellar (LAM-uh-ler) keratectomy, in treating diabetic retinopathy (ret-in-OP-uh-thee), surgeons may use an argon laser to slow or stop abnormal growth of blood vessels in the retina. Another retinal procedure is the vitrectomy (vih-TRECK-tuh-me), where the vitreous material of the eyeball is removed, and the space refilled with a replacement fluid. In those with cataracts, the old, cloudy lens is removed, and an artificial intraocular lens is implanted. Many glaucoma surgeries now use a laser to make a hole in the iris, allowing drainage of excess fluid. Age related macular degeneration can also be treated by laser, in a technique that seals off diseased blood vessels in the retina. In fact, laser procedures are increasingly popular, as they tend to give more precise results, with a shorter healing time.