I was taught at an early age to shoot 'traditional', i.e. using one eye open. I'm a lefty, and back then my right eye was my dominant eye. I shot rifle right handed and pistols left handed. When I had to qualify with a 45 in the Corps, a shooting instructor taught me to shoot a pistol with both eyes open, and to shoot right handed. Seemed very natural to me. Now I shoot pistols with either hand, and either eye, although I've trained my left eye to be my master eye now and use it almost exclusively as I have some damage to my right eye's cornea and it messes with my RMRs.