The important thing to know about these two procedures is that the exact same laser treatment is applied to the cornea and the exact same result should be expected. Long term studies of both have proven this to be true. The difference is that Lasik is performed underneath a corneal flap, which, in my practice, is laser made. This results in quicker healing and visual improvement. PRK is performed directly on the corneal surface, so, while the visual results will be the same as Lasik, there is more healing involved, and some additional discomfort and a longer healing time. In my practice, I tend to perform PRK about 10% of the time, and reserve it for those people who have thin corneas or other conditions that prevent them from having Lasik. My patients tend to prefer Lasik becasue of the rapid visual and comfort recovery.