I'm not trying to add to the bad gouge on this sight, but from what I saw going through the program if you want to be a pilot, get that SNA slot before you get into the pipeline. I knew a few guys who were "NPQ'd" from SNA for various reasons but managed to appeal succesfully. However, at least when I was going through, if you comissioned with an SNFO card the odds of crossing over were slim-to-none. The obvious exception being the guy who ranked first in his API class, but even then only if they didn't need any waivers. It seemed like waivers were readily available for pilots already in the pipeline, but not so much for the other guys. Moral of the story: if you are offered a pilot slot take it and let NAMI take care of itself.
By the way, as an interesting footnote, my eyes change about every year so that about every other year I get a "corrective lenses required when flying" chit. Then it goes away the next year. I've never worn glasses when flying (except my Maui Jim's) but I did wear BCGs at OCS for a couple of weeks. I've never figured out why it works that way.