Honestly I use my non-dominant (right) eye, for both open sight and scoped work. I find that with the right (read: scoped and intrinsically accurate) rifle I can still shoot sub-moa, and I'm blind enough I never measure when shooting pistols. I can also hit torso-sized objects open-sighted with my AR out to 200 yards or so, without my corrective glasses. Your Mileage, as always, May Vary, but that's my $.02 on the matter.