What's the difference between regular and epi-lasik?

Not much!: Lasik is the laser vision correction procedure done after a flap of cornea is created and reflected out of the path of the laser. In lasik, the flap is created by a microkeratome or femtosecond laser and is about 90-160 microns thick. Epi-lasik also makes a flap but only the much thinner epithelium, or surface layer, is removed by a mechanical epi-keratome. The basic difference is flap thickness.

Epi-LASIK: In lasik, a flap is created in the cornea which is then lifted to allow the laser to be performed. In epi-lasik, no flap is created but a sheet of the surface cells (epithelium) is removed to allow the laser to be performed. This sheet can either be replaced or discarded depending on surgeon's preference. Epi-lasik is similar to prk (photorefractive keratectomy) or surface laser.