LASIK represents the combination of two separate procedures: 1) making a corneal flap, and 2) sculpting the cornea under the flap with a laser. In the first step, the surgeon uses an instrument called a microkeratome to make a hinged corneal flap. The flap is folded back exposing the bed of the cornea. In the second step, a cool laser beam sculpts the curvature of the exposed corneal by evaporating tissue. Then the corneal flap is repositioned and it adheres without the need for stitches. Visual recovery is typically rapid. Microkeratome technology has existed for nearly 50 years while the excimer laser was first applied to the human eye in 1983.

LASIK can treat both myopia and hyperopia with or without astigmatism. Before 1999, all LASIK was performed “off-label”, meaning the FDA did not approve its use. The FDA approved myopic LASIK (with or without astigmatism) in late 1999 for the Summit Apex Plus and VISX Star S2 lasers. Other lasers are also approved for myopic LASIK.
Meanwhile, excimer lasers have also received approval for hyperopic LASIK (with or without astigmatism). The Autonomous LADARVision system received this approval in September of 2000. VISX received the nod from the FDA October of 2000 for PRK and subsequently for LASIK.