The Cleveland Clinic

Overview of Refractive and Laser Eye Surgery

Introduction

Vision repair surgery, also called refractive and laser eye surgery, is any surgical procedure used to correct vision problems. In recent years, tremendous advancements have been made in this field. After refractive and laser eye surgery, many patients report seeing better than they had at any other time in their lives.

All refractive and laser eye surgeries work by reshaping the cornea, or clear front part of the eye, so that light traveling through it is properly focused onto the retina located in the back of the eye. There are a number of different types of refractive or laser eye surgeries used to reshape the cornea, including:

  • LASIK: Short for laser in-situ keratomileusis, this laser eye surgery is used to correct vision in people who are nearsighted , farsighted , and/or have astigmatism . During LASIK laser eye surgery, vision is corrected by reshaping underlying corneal tissue so that it can properly focus light into the eye and onto the retina. LASIK laser eye surgery differs from others in that a flap is made in the outer layer of the cornea so that the underlying tissue can be accessed.
  • PRK: Short for photorefractive keratectomy, this laser eye surgery is used to correct mild to moderate nearsightedness, farsightedness, and/or astigmatism. During PRK laser eye surgery, an eye surgeon uses a laser to reshape the cornea. This laser, which delivers a cool pulsing beam of ultraviolet light, is used on the surface of the cornea, not underneath the cornea, like in LASIK laser eye surgery. Therefore, no cutting is required.
  • LASEK: Short for laser epithelial keratomileusis, this is a newer form of laser eye surgery that combines many of the benefits of LASIK and PRK. However, unlike LASIK and PRK laser eye surgeries, there is no cutting or scraping of the eye. Instead an epitheal flap is created using a 20% alcohol solution. LASEK laser eye surgery is used to treat nearsightedness, farsightedness, and astigmatism.
  • ALK: Short for automated lamellar keratoplasty, this eye surgery is used to correct vision in people with severe nearsightedness and slight degrees of farsightedness. As in LASIK laser eye surgery, a flap is created in the cornea so that the doctor can reach the underlying tissue. However, during this procedure, a laser is not used to correct vision. Instead, another incision is made on the sub layer of the cornea to reshape the cornea.
  • LTK: Short for laser thermokeratoplasty, this is a new laser eye surgery is used to treat farsightedness and astigmatism. During LTK laser eye surgery, a laser beam uses heat to shrink and reshape the cornea. Vision is corrected in a matter of seconds, without any cutting or removal of tissue.
  • AK: Short for astigmatic keratotomy, this is not laser eye surgery, but a surgical procedure used to correct astigmatism. The cornea of people who have astigmatism is shaped like a football. AK eye surgery corrects astigmatism by making one or two incisions at the steepest part of the cornea. These incisions cause the cornea to relax and take a more rounded shape. This eye surgery may be used alone, or in combination with other laser eye surgeries such as PRK, LASIK, or RK.
  • RK: Short for radial keratotomy, this eye surgery was once one of the most frequently used procedures to correct nearsightedness. However, since the development of more effective laser eye surgeries, such as LASIK and PRK, RK is rarely used today.