Here's what I know with regards to eye surgery and aviation:
For SNA:
uncorrected each eye must be 20/40 or better, correctable to at least 20/20 each eye if not 20/20 uncorrected
For SNFO:
uncorrected: no limit but must be correctable to 20/20 each eye
Surgeries:
If you get LASIK or PRK, then your new "uncorrected" vision is whatever you see without glasses after surgery. They might now be starting to recommend LASIK over PRK for most patients if you qualify for both. Uncomplicated LASIK that gets you to 20/20 or better will NOT disqualify you from any aviation platform.
Waiting period for commissioning waiver after LASIK or PRK: 6 months
Waiting period for NAMI after LASIK if you get it done after commissioning: 1 month-ish, although it can be sooner or later depending on healing
Waiting period for NAMI after PRK if you get it done after commissioning: 3 months I think
It's my understanding that USNA likes to do LASIK or PRK before 1/C year to allow time for recovery, waivers, etc. They might do it during 2/C year or in the summer? Not sure when exactly, but the Navy pays for it if you're a USNA mid. For NROTC, you have to pay for it on your own, unless you get it done after commissioning down in Pensacola.