. >> so what prc is, procedure where you remove the very surface layer of the cornea, scratch son theornea, then you shave down the top of the cornea. with lasix what you're doing is taking either a blade, maybe you had a blade procedure, years ago, now often time it is done with a different lazer, that creates a flap. so it cut maybe 20% of the cornea, with the flap that has little hinge on the side. so take that flap, move it over to the side. then you use the lazer, same lazer as prk to shave down the middle of the cornea. then you put the flap back. >> so prk the flap doesn't go back? >> there is no flap. there is just a big scratch on the cornea. and that scratch heals over the next few days, after surgery. >> snow would he have this so he could see down the field better both of these surgeries, prk and lasix, ends up with the same result. most people looking for good distance vision. >> yes. >> un corrected distance vision. it is just different ways of shaping down, shape, reshaping also differences in the recovery, more down time with the prk? >> the disadvantage to prk, are th