I'm a strong believer in keeping both eyes open. No matter what eye is dominant there should be no double vision. Your focal point is the target not the barrel. The barrel should only be seen in your periphial vision. By closing one eye you cannot judge depth perception and you are probably seeing the barrel way more than you should. Would you close one eye to throw a football? No, you keep both eyes open and your body automatically calculates distance and lead in order to hit the reciever. Same with shooting sc. Like anything, this will take some time getting use to but in the long run you will be much better off (especially when your eye sight goes to hell). Don't get me wrong, I don't want to discredit anything that works for you because that is really all that matters. Have fun with it.