LASEK or laser sub-epithelial keratomileusis is a refractive surgery procedure for treatment of myopia and astigmatism. A very thin layer of the corneal epithelium, the most superficial layer of the cornea, is detached using an instrument called a trephine. The flap is moistened with a diluted alcohol solution and folded back. Next the ultraviolet light and high-energy pulses from an excimer laser reshape the cornea and then the flap is returned to its original position. A contact lens is placed on the cornea to aid in the healing and to reduce pain.
Advantages of LASEK over PRK
- Less postoperative pain and haze
Advantages of LASEK over LASIK
- May be performed in some patients whose corneal shape or thickness does not permit safe performance of LASIK

