Ok, talking as someone who actually has professional instruction on this stuff. If you are shooting a handgun, simply move the gun to your left eye, you don't need to #### your head, or switch hands. shoot right handed, and move the gun over slightly. if you are right handed stay right handed. it's a waste of your time to try and do it left handed, and pointless. If you are shooting rifle you can get away with closing or putting a piece of tape over your left eye (if you shoot with glasses use the tape to blur the left eye) and then shoot with the right eye. if it's really bad and you can't do that, then yes you may have to shoot rifles left handed. But for handguns there is no need to.