I was 20/400 before PRK. I had it done in 2003 at age 36. PRK was the only option for USAF aviators at the time. They got me to 20/15 and on a good day, I could hit the 20/10 line. I lost some near vision right away and within 6 years I would need reading glasses to read my checklist under a dim finger-light at night. Oddly, 2 years ago during a flight physical, I passed the near vision test without cheaters and had an unrestricted medical certificate. I still carried cheaters every flight! The last 2 years has seen a fast degradation of my near vision. I can see a computer keyboard well enough but cheaters make it more comfortable. The screen I see fine unaided. I am still 20/20 and 20/15 well rested and hydrated for far vision.
I started shooting again this year and discovered I can not focus sharply on the front site with my right eye. It is much better with my left (dominate) eye but I'm right handed. I was getting OK groups but nothing like I was used to on active duty with the M9. On day at the range, for sh$ts and giggles, I put out 3 rounds with my cheaters and got a dime sized group on the bull out of my Glock 20 at 7 yards. It works for me YMMV. I have no problem shooting effectively with both eyes open on a silhouette. Focus is on the target in that mode anyway.
Would I do it again knowing what I know now? Heck yeah! I might have waited to get Lasik instead though. PRK takes longer to heal and I had some issues in that area. One of my corneas took longer to close than it was supposed to and was very painful. Still if PRK were my only option, I would do it again. I have no halos or other artifacts. Most of my peers I fly with all have cheaters for reading so that may have been unavoidable in any case. Good luck to you and if you decide to do it, post back here with an update or two. I'm sure there are many folks who have the same type questions who just haven't asked!