When I was a ROTC cadet, pilot candidates could not wear glasses. Once you got your wings, no problem (just like allergies).

The Academy guys could wear glasses. 20/70 correctable, I believe.

The Guard could get waivers if they wanted them; same in the Reserves.

That leaves OTS: I think they were like ROTC; couldn't wear them until after you were winged.

I believe, but am not positive, it still depends upon your source of commissioning.

And I think you meant Guard, not 'Gaurd.'