OBH, first, welcome to the forums. You won't get better advice anywhere on the web then the guys right here.

A good shooting coach will tell you to teach the boy to shoot to his dominant eye. He's young and you have the opportunity to teach him the right way to shoot rather than have him struggle with it later in life. You'll be doing him a favor having him shoot to his dominant eye because one should shoot with both eyes open tho many great shooters don't and some great shooters shoot opposite of eye dominant. BUT with the opportunity to teach/mold your boy into the best shooter he can be, I'd opt to teach him to his eye dominance.

The other option is to patch his left eye when he shoots.

<font color=blue>Good Luck and Good Shooting</font id=blue>

<font color=red>Rob</font id=red>