LASIK permanently changes the shape of the cornea. The surgery is performed using a topical anesthetic (drops in the eye). The procedure involves folding back a thin layer of corneal tissue (corneal flap) with a microkeratome (a surgical instrument much like a carpenter's plane). Once the flap has been made, a thin layer of corneal tissue is removed with the light from the excimer laser.
After removal, the flap is replaced and bonds back into place. The removal of thin layers of tissue causes the center of the cornea to flatten in the case of nearsightedness, or steepen in the case of farsightedness or become more rounded in the case of astigmatism, which changes the focusing power of the cornea.
|
