I am an eye doc, and eye dominance is a funny thing. Not everyone has a true dominant eye. There are levels of dominance just like there are levels of dexterity with your hands. I know some folks who can write equally well with both hands, some learned and some just natural. You cant really "teach" eye dominance, but you can learn to ignore input from one eye to an extent. Where this can play to my advantage or give me the biggest headache imaginable is with folks being fitted in multifocal contact lenses. Sometimes I wanna pull my hair out with that shit.
Dave