In the LASIK technique, a special instrument known as a microkeratome (which has a blade which oscillates at high speed) is used to cut a hinged uniform thickness flap on the cornea. The flap is usually 100-130 microns thick. This flap is then lifted to one side to expose the stroma, and the excimer laser corneal reshaping is carried out. The flap is then replaced in its original position, where it sticks in place within a few hours. The only place where the epithelium is damaged is along the flap edge. This takes a few hours to heal, and so the pain after the procedure is both less intense, and for a much shorter duration than after PRK. Since the original epithelium in the central cornea is smooth, full thickness and undamaged, vision recovery takes a few hours, rather than the days and weeks it takes after PRK. Since the corneal stroma is not exposed to the tear film at all, there is practically no likelihood of haze and regression. And the susceptibility to infection is much less.

So LASIK directly addresses the problems of PRK. It is relatively pain free, the results are better and more stable, and vision recovery is quick.

However, LASIK is not without its problems.

Next: LASIK, Possible Problems