My son's problem is a little nuanced. His vision is 20-20 uncorrected, but only because his dominant right eye takes over for his 20-60 left eye.
Try this link. http://www.usna.edu/Catalog/2005-2006organization.pdf
Check Page 8 for the vision information. It doesn't give much information but it specifically says any type of corrective surgery is an automatic disqualifier.
hmmmmm,.... sounds like the regs need to be checked out.