Hmmmm... I don't believe the prism can be switched on eyes, because the entire tech is one component in a right side plastic housing. (see closeup pics). Also, in the one demo I attended, I don't ever recall seeing a Leftie's version of it. The entire line was a Beta product for early adopters before the major roleout.
Now, you will lose the little cube screen thing, but honestly that little screen didn't provide much functionality. If you get one for the camera / video and audio function you'll likely be fine.
Although, you may be better off getting a Smartphone watch. I'm curious what makes you want to get Google Glass? I followed them for a while, but the product got nowhere near what they showed in the demo-videos, which was a...