My father dictated that I was to learn how to do all tasks right-handed, even though I am a lefty. Consequently, I now shoot right-handed but have a dominant left eye.
It wasn’t until I began practicing at extended ranges that the situation actually became a problem. Depending on which eye was working at the time of release, I produced two horizontal groups at ranges of 30 yards and beyond.
Surfing the net I stumbled across an ad for a “shooter’s occluder” designed for target rifle and pistol shooters; in essence it’s a shield that clipped to the frame of one’s glasses or cap to block the vision of the unused eye. Further research showed that the mere act of closing the unused eye stresses the face muscles and produces distortion and fatigue in the eye intended for work. I also found research proving that darkly occluded eyes send confused messages to the brain that produce poorly focused images from the eye being used (more fatigue and poor sighting).
Being the eyeglass wearer and cheapskate that I am, I traveled to the local department store, bought a pair of clip-on, flip-up sunglasses and retired to the shop. A pair of diagonal cutters made short work of the right lens and electrician’s tape blacked out the left.
Man, was that a relief! All of a sudden I had one group at all ranges! The only problem was that as dusk approached, I had extreme difficulty getting my aiming eye to focus. Then I remembered the research about the black occluder. I replaced the electrician’s tape with lighter colored masking tape–what a difference!
Now I clip my occluder to my eye glasses, flip it up when not in use and flip it down when anticipating a shot. I have no face fatigue and my groups improved dramatically. If one of those long-toothed dangerous White Tails were to sneak up on me unexpectedly, I would just cover the offending eye and shoot. The only downside is that my neighbor accuses me of being one of the “Borg” when he sees me practicing.