I had PRK a year and half done into my second tour flying Hornets for the Navy. I wouldn't trade it for the world. PRK has many more benefits, mostly in terms of long term side effects, over it's LASIK counterpart, especially with night acuity issues. The Navy currently is conducting several studies with LASIK for aviators, but to date it is NOT approved for Naval Aviation(USMC/USCG as well). One thing you must consider for military aviation before getting PRK is that your initial refractive error will determine if you are eligible for a waiver regardless of your PRK outcome(read: If you're correction is large, and diopters are big numbers, you may be disqualified from flying).

As for your FAA exam you're fine as long as you can pass the test. I had no issues. I'm 20/15 in both eyes now nearly a year and a half after the procedure. I was 20/40 and 20/50, but was 20/100 in both eyes when they were dilated. My eye muscles were compensating alot. Now, life is good, and NO night issues. The week worth of pain and 90 days of not flying was well worth the reward.