Is there any research (not wild conjecture) on staring at a screen strapped to your face for extended durations? I am already near sighted from having spent a lifetime focusing on a screen an arm's reach away. What happens if there is no chance of errantly focusing on other objects and forcing my eyes even a modicum of daily activity?
The optics put the virtual image (if you remember physics class) of the screen about 1.2 meters in front of your eyes, not inches. Your eyes lens/focus muscles will be set just as if you were focused on something actually 1.2 meters.
