Like a few others, I had this issue develop. I have had PRK done twice, and my eye dominance over the past few years has shifted from my right eye to my left eye, as my left eye has been able to be better corrected. Previously I was always able to shoot pistol with both eyes open, but over the last 4 years or so, have found myself having to squint that left eye now to keep things clear and not have my brain fight which sight picture is correct. I've spent too long shooting right hand and right eye to switch over my dominant hand at this point, so I have moved into squinting my left eye. As far as shooting I see no difference- it just diminishes my peripheral vision as you would expect. Luckily with rifle I don't have the eye dominance issues like I do with the pistol, so I guess my brain doesn't have any issues with a red dot optic at that distance.