In USPSA, while we don't use eye covers in a match, but a lot of competitors will use them on their dominant eye to practice fast target acquisition, independent of their pistol red dot or iron sights. Translates to very refined muscle memory when you don't need to rely on your optics to align your aim.
In most type of shooting, you're generally NOT closing either of your eyes while aiming. It's counter productive to your situational awareness
Sometimes a white opaque shield is used, on the theory that allowing light through won’t have potentially negative effects on iris contraction. I can’t speak to the validity of this one.
Both eyes are preferred for a killer, because you want to have awareness. But it is not an easy way to shoot, or train, or learn.
On another note, I had a cal .22 blow on my face once, on a perfectly tuned rifle, and the reason I kept my eye, is because the exit is on the right hand side. Most rifles are build like that.
I think you're entirely wrong, but the sport USPSA is vastly different from any Olympic style shooting you would seen. It's speed and hit factor (that is, the caliber of your gun as a TLDR). Different priorities than Olympic sharpshooting.
For him it helps to block his non-dominant eye as he has a weak dominant eye.
Also, the pupil responses are linked, so you'd want both eyes to be exposed to similar brightness. So you don't want to close it or wear a patch.
Cargo cult, even at the olympic level, is a thing. See the mustaches that make you swim faster [1]. It wasn't only the Russian's that adopted it.
[1] https://swimswam.com/the-legend-of-the-mustache-in-swimming-...
Since I lost my left eye I have no trouble looking through only one eye. However, I have acquired plenty of troubles with balance.
You don’t have to track target, as it’s always in the same spot.
What I’m curious about is the rapid fire Olympic event. It’s not particularly fast as these things go but very accurate (though less so than the other events).
In other words it is not like you are holding a tiny dot in the exact center of a circle, it is a messy blur of trying to hold 3 things in alignment where the front sight is about as big as the entire bullseye (hence why you aim below, so there is white visible, you would otherwise obscure the target entirely.
If you do it well, you are consistently hitting something the size of the period at the end of this sentence from 10 meters away (again, air pistol).