PRK vs LASIK

You can find information on the differences and similarities between PRK and LASIK all over the interwebs, but I might as well give a quick summary here. Both use an excimer laser to ablate portions of your cornea, which changes the way that light is refracted into you eye, through your lens, and onto the retina, from where it is transformed into signals your brain can interpret as images. The difference between them is that with LASIK, a tiny blade or another type of laser is used to make a flap out of part of your cornea. This flap is then laid back out of the way so the excimer laser can go to work on a deeper layer of your cornea. Once that's done, the flap is put back in place, giving you almost instantly improved vision. Apparently, discomfort is minimal and healing is very quick. I know several people (including my sister) who have had LASIK done and loved it. They were all back up and at 'em the very next day.

With PRK – photorefractive keratectomy – the procedure is different. In PRK, no flap is created. Instead one means or another is used to remove your corneal epithelium, the thin transparent layer of skin that covers your cornea. In my case this was done with a kind of brush, which the surgeon initially described as similar to an electric toothbrush. Once the epithelium is removed, the excimer laser goes to work on the surface of your cornea, thus the term “surface ablation.” Because no flap is created and the surface layers of your cornea are reshaped with the excimer laser, PRK is supposed to leave your eye structurally stronger than LASIK. There's also no risk of dislodging the corneal flap in the future (which I'm told is very rare and requires a lot of force, as in from an airbag in a car crash, but nevertheless a possibility). On the other hand, PRK is less comfortable (some would say “more painful”) than LASIK and requires a substantially longer healing period before patients can work again. I was told to expect up to two weeks of very blurry vision preventing me from reading either at distance or close up. You can see a video of PRK on youtube here.