Thanks for the ping. Beside training and experience, one of the important factors in WW-II was the pilots’ eyesight. For example, Chuck Yeager had 20/15 vision.
The baseball player, Ted Williams, was a Marine fighter pilot in WW II and in Korea. He achieved, I believe, ace status.
In baseball, his eyesight was fabled. He claimed to be able to see the bat hit the ball. Many umpires keyed on his perception of the strike zone -- if he swung at the pitch, it was a strike; if he kept the bat on shoulder, it was a ball.
I seem to recall rumors that his eyes tested at 20/10.