The ‘flap and zap’ method, or LASIK (Laser In-situ Keratomileusis), involves treatment in the middle of the cornea. By this technique, a thin flap of the corneal tissue, which includes the surface cells, is first made with an automated instrument, or a femtosecond laser. This flap is hinged and is folded back so that the laser treatment can be applied to the stroma. Once the laser application is completed, the flap is replaced and sticks back into position within a few minutes.

LASIK treats the surface of the cornea once the epithelium has been removed. Vision improves with LASIK over a few days.

LASIK treats the inner surface of the cornea after a flap has been made within the corneal tissue with a very accurate blade or femtosecond laser. Vision improves overnight.