If you had head mounted cameras, they could feed depth info to layer the UI, as you say. And if the display is covering your eyes completely, then feeding video

If you had head mounted cameras, they could feed depth info to layer the UI, as you say. And if the display is covering your eyes completely, then feeding video in...? We don't get to see what the guy looks like, just what he's seeing. Maybe he's got 15lbs of Heath Robinson equipment on his head.