I don't believe this was the UI that was eventually released, but I got a demo of an Glass prototype where the way to interact was to focus your vision on the b

I don't believe this was the UI that was eventually released, but I got a demo of an Glass prototype where the way to interact was to focus your vision on the buttons in the corner of the virtual screen to click. When the guy told me that, at first I thought "you've got to be kidding me" and very shortly thereafter it was "holy shit this is awesome." That reminds me, a couple years ago I ran into a guy working for a company that could wirelessly power displays in a contact lens. Not remotely practical and I think it was maybe a couple hundred pixels at most, but definitely more of that living in future vibe.