i used to be a left eye shooter when i only shot SLRs. when i bought my first rangefinder. it just seemed more comfy using the right eye, but i couldnt see worth a dang with my right eye in the view finder. but i just kept at it and my eye adjusted itself within a few days.
the moral is, even if it feels uncomfy at first, if you give your eye a chance, it will adjust itself so that using that eye on the viewfinder becomes no problem.
now i use both eyes. horizontal shots, i use right eye. vertical shots (i hold the camera with shutter button on the bottom), i use left eye. for SLR, both left and right depending on how i hold the camera.
give them a chance and you'll be able to use both eyes, the right one for each circumstance.
