I have a slightly different problem but the fix is similar. Sometimes my eye dominance will shift. I am right eye dominant and right handed. Occasionally, over a day of shooting zz birds or trap my eye dominance will shift and I will start missing targets. I really think my brain gets bored. At the suggestion of Cyril Adams, my fix has been a greasy finger print or chap stick smear on the left glass lens to force the right eye to see out of the clear lens. Now that I have I figured out what happens, I just smear the left lens before I start. It doesn't happen in field shooting or sporting clays.
