Refractive surgery encompasses a variety of technologies and procedures for correcting several common eye conditions such as myopia (nearsightedness) and hyperopia (farsightedness).
The surgery changes the focusing characteristics of the eye to achieve a clearer image. These surgeries may change the shape of the cornea, implant an artificial lens, or alter the eye in other ways.
Three forms of refractive surgery are now commonly available in the U.S.:
or RK as it is often called, is one of the oldest forms of refractive surgery. In RK, an eye surgeon usually uses a scalpel to make from four to eight tiny cuts into the cornea. The cuts are arranged like spokes on a wheel. The cuts allow the cornea to flatten, lessening its focusing effect on the light entering the eye. This process is most commonly used to correct nearsightedness.
PRK, is a more recent development in refractive surgery. Like RK, PRK changes the shape of the cornea to correct problems like nearsightedness. In PRK, however, a laser is used to remove the outer layers of the cornea to create a flatter shape. The laser instrument used in PRK can also re-shape the cornea to correct conditions like nearsightedness and astigmatism.
is an acronym for Laser In Situ Keratomileusis. LASIK is another type of refractive surgery that uses a laser to reshape the cornea. Rather than removing the outer layers of the cornea like PRK, a surgeon performing LASIK first uses a special cutting instrument to cut a thin flap into the top of the cornea. This outer flap is folded back and the exposed inner tissue of the cornea is then reshaped with the laser. Afterward, the flap is folded back into place. This preserves the outer layers of the cornea and helps to speed healing.