So pilots have to have 20-20 vision. But those who drive don't, yet on the road people have to read traffic lights, signs, see other cars' turn signals, and watch out for bikers and pedestrians. Okay, makes sense.
So why DO pilots have to have 20-20 vision? They have the control tower telling them what's coming, and they look out and just see a fog anyway. So they need perfect vision to see the controls in the cockpit just a few inches away from them?
In that case, men should have to have 20-20 vision in order to engage in any sexual activity. I've had situations where it was like, "Ouch, that's my NIPPLE. It's small and delicate, so why the hell are you treating it like it's a popsicle??!"