pwolfman, I always shoot with both eyes open. Peripheral vision and depth perception is too important in Personal Defense, IMO, to degrade or eliminate by closing one eye.
My left eye is very dominant, so it's easy for me to "capture" the front sight with my left eye when I bring the pistol up, even with my right open. Attempting to train my right eye to take on a dominant role has not worked for me at all.
I agree with pax...knowing and retaining the skill of how to shoot with either hand is a great idea that may well save your life one day. Also, if you wear glasses, practice without them just as much as with them.
As far as shooting left-eye dominant and right-handed, try this exercise yourself. When I'm doing this, I always remove mag, clear chamber, then remove all ammo from room. Then, bring the pistol up right-handed, align with the left eye keeping the right open, and look in the mirror. I'll bet that your pistol isn't canted more than a few degrees to the left of vertical.
Difference in your accuracy should be negligible, but only you are going to be able to determine that at the range. If you have enough range time available, do two runs:
- Left-handed, left eye dominant, both eyes open
- Right-handed, left-eye dominant, both eyes open
That will give you some good data to work with by comparing accuracy of the two runs.
I'm meandering, so let me try and summarize what has worked for me. Don't mess around with your left-eye dominance. Keep both eyes open. Use right or left hand depending on what works best overall for you.
[edit for clarity]