Wiktionary
n. (context surgery English) Improvement of the refractive state of the cornea, performed by cutting a thin hinged flap in the front surface of the eye and lifting it to access the cornea.
Wikipedia
Keratomileusis is the surgical improvement of the refractive state of the cornea performed by lifting the front surface of the eye by forming a thin hinged flap under which the shape of the cornea is changed by using an excimer laser or other surgical device, and was developed by José Ignacio Barraquer, commonly called "the father of modern refractive surgery." A microkeratome is usually used to cut the flap, but a femtosecond laser can also be used to make the flap. Before the advent of the excimer laser, keratomileusis was performed using a cryolathe, which froze thin flaps of corneal tissue and lathe cut them much like one cuts the lens of a pair of glasses. After thawing, these reshaped flaps were placed under the front flap to correct visual improvement. LASIK is currently the only commonly performed keratomileusis procedure.