Few things:
1. Yes there are waivers. Timing can be everything though on if they give them out. I went through UPT with a guy on a depth perception waiver.
2. I'm like the other poster, always failed the circle test, got sent to the optometrist and passed their test with no problem. Make sure they are sending you to an actual optometrist, not stopping with the circle test.
3. Make sure prescription is spot on. If mine was off slightly I would not pass, but once corrected, I had no problem.
4. Since you are not in yet, no one will be too proactive in helping you with a waiver. Be persistent. Don't take initial answers of "that's not possible" Ask for supervisors and regulation references. Be persistent to the point of being annoying (but professional).
5. Good luck.