Surf Monkey
Suspended
I don't have (and never will) an AVP, but my understanding is that for your eyes it's all screen that show the windows layered onto a display that shows the outside world. While the windows may be scaled on to the screen to look 6 feet away relative to everything else on the screen, the actual light source that your eye uses for focus is still only a few inches away. It may fool your brain, but your actual eye still has to focus on something that's very close for the entire time.
Even if your eyes are focused at 6 feet that’s still not enough. You need to look into the distance. 20 feet or more about every 20-30 minutes.