I don't know how relevant this is but I am right handed and left eye dominant. I shoot pistols w/ my right eye closed. If I try shooting both eyes open, I see 2 sets of sights and 2 bullseyes. My shooting glasses have the entire left lens focused at front sight distance. The right lens is my standard bifocal. The interesting thing is that at a match I put my 'special' glasses on and things look weird for a few minutes. I have never timed it but it seems to take my brain maybe 3-4 minutes to adapt to the new lenses. Then all is well and that FO front sight looks like it has a 100 watts coming through it. After the match I go back to my regular glasses and it takes the same 3-4 min for my brain to readjust.