I'm 22 and I just got PRK 4 weeks ago to earn an OCS flight slot. The minimum age is 18 with most surgeons. The surgeon usually wants you to have a stable prescription, but it's at his or her discretion. I went in and was told I was a perfect candidate for PRK, so I suggest just visiting a doctor. Before surgery my eyes were about 20/70, and last week I was measured at 20/15 in both eyes. Truly amazing stuff, I highly suggest it.

P.S. I wouldn't bargain shop when it comes to eye surgery, go with the best surgeon in the area.