Here's the straight dope: vision is generally not waiverable, in my experience. Yes, some obscure conditions can be waiverable but, for the most part, if you want to be a Student Naval Aviator, your vision must be 20/40 or better, and correctable to 20/20. In layman's terms, your vision needs to be really good. To qualify as a Student Naval Flight Officer, I don't think there are refractive limits uncorrected, but it needs to be correctable to 20/20. SNFOs generally don't pilot aircraft after doing it a little bit in flight training, so the limits uncorrected are more lax.
So while it doesn't sound like you qualify for SNA, barring any other issues coming up, it seems like you have a shot for SNFO. If that's a dealbreaker get PRK. Your vision, though, sounds likes it fine to start an officer accessions program like NROTC. You could always get PRK, with your ROTC command's blessing, once you're in NROTC. NROTC midshipman don't select a designator until later in the program, I don't think. But, I'm an OCS grad, so I'm not 100 percent sure about that -- pretty sure though. Both SNA and SNFO are great designators which would put you in the brown shoe Navy, if that's what you desire. It depends on what you want to do. Hope that helps.