Even with trifocal lenses in my Rx glasses, I typically keep both eyes open for any kind of shooting. I kind of just blank out my non-dominant eye which is my left eye.
Yesterday, for the first time in my life, I needed to take a shot at a woodchuck with the gun against my left shoulder and using a scope with my left eye, as there were leaves from a maple tree blocking the scope's view with the gun on the right shoulder, so I had to improvize. I should practice that shot more often. I did hit the critter, however before I found him collapsed in a pile of large rocks I thought he might have gotten away! This was out of a roof window and the 'chuck was on my back lawn stone wall near my wife's vegetable garden. No woodchucks get to live near her garden, that is an unspoken rule we have.