Not sure where you guys with the bad eyesight are from, but at least in the US it's a non-issue, unless you're trying to be a pilot. As long as your vision is fine with a pair of glasses, it's not a problem, nor should it be.
I mean, I'm both near-sighted and have pretty heavy astigmatism, and might as well be half-blind without my glasses, but I have no problem laying down accurate fire 500 yards downrange
