LASIK or Laser Assisted in-Situ Keratomileusis treats refractive errors by removing corneal tissue beneath the surface of the cornea. This procedure combines the accuracy of the excimer laser with the benefits of the Lamellar Keratoplasty (LK) in which an instrument called a microkeratome allows the surgeon to fold back a thin layer of the cornea.
Then the excimer laser removes the proper amount of corneal tissue with much greater accuracy. How much tissue is removed is controlled by the number of pulses and the size and shape of the laser beam. The thin flap of corneal tissue is then folded back into its original position where it bonds after only a few minutes of drying. No stitches or eye patches are required after the procedure.
Since only the edge around the corneal flap needs to heal, visual recovery is rapid and patients report little or no postoperative pain. Additionally, there may be less risk of scarring and developing corneal haze. There is also less need for postoperative medications with LASIK than PRK. However, because of the microkeratome, LASIK carries additional surgical risks.
LASIK also treats low to moderate amounts of nearsightedness, farsightedness, and astigmatism.