Ideally, you should keep both of your eyes open when shooting. Now, it’s not impossible to shoot one-eyed. The great trapshooting champion Nora Ross shoots with one eye shut tight. And, while there’s no question that Nora would beat me in a shooting match, think of how much worse she’d beat me with both eyes open.
Nevertheless, some people who have shot on the wrong side (not their dominant-eye side) for too long can’t or won’t switch no matter what. Some are center-dominant, and if both eyes are equally strong, each eye will take over at different times.
To determine your dominant eye, hold your arms extended, palms out with both eyes open, making a hole between your thumbs that frames a distant object. If you’re right- or left-eyed, the object will disappear when you close your dominant eye.
Center-dominant people often see the object no matter which eye they close. They need to close an eye when shooting or, better, place a small patch of dark tape on the off-side lens of their glasses. The tape patch can be about the size of your thumbnail. If it’s placed just right to block your vision when you mount the gun, it’ll be high enough that it won’t interfere with your vision when you have your head up normally.
Whatever the case, it’s much better for a new shooter to learn to shoot from his or her dominant-eye side, even if it means pulling the trigger with the non-dominant hand. I taught my older, right-handed, cross-dominant son to shoot left-handed, and he does very well in the field. He’s never handled a gun right-handed at all.
The reason to switch sides and be able to shoot with both eyes has nothing to do with depth perception or peripheral vision, in my opinion. It’s simply that if you shoot with one eye closed, you see the gun in sharp focus. And the better you see it, the more likely you are to aim it—which is the worst way to shoot a shotgun. Your eye-hand coordination and subconscious mind are much more effective at putting a gun on target than your conscious, aiming mind can ever be. With two eyes, you can “see through” the gun, and it appears as more of blur, allowing you to keep all your focus on the target, where it belongs.
The advantage of shooting with both eyes open from your dominant side was borne out in a shooting test I conducted last year. In the test were four shooters who normally shot with both eyes open (and from their dominant side).
The shooters all shot a round of five-stand as usual, then taped their glasses to block their non-dominant eye and shot another round. Blocking the non-dominant eye resulted in an average 18-percent decrease in hit birds.
One other shooter who was cross-dominant, and who normally shot with one eye closed, shot with both eyes open and saw a 36-percent decrease. Nevertheless, most people aren’t cross-dominant and will hit more targets by shooting with both eyes open.