
When I shot pistol matches, I shot with both eyes open. Pretty much mandatory to do that for quick target aquisition. But it did (and still does) seem easier to get a sharper focus on the front sight with both eyes open with the handgun.
Try as I might, I have an impossible time keeping both eyes open when shooting a rifle, no matter what style of sights, or with a scope. And especially so with any of my peep sights.
I do know this: After only a few shots when looking through a peep, my right eye gets watery, and focusing on the front sight gets really blurry. And groups go to poop after that......
