Depends on your eyes, bro. Some folks aren't that dominant in either eye and can switch at will. Most are not so lucky. That leaves them adapting when they shoot cross-dominant, i.e., firing left-handed with a right master eye.
The following may be of help in the latter case:
http://www.glocktalk.com/forums/show....php?t=1418553
Hoping the above is of help,
Mas