So you want a 16MP @60fps video camera and a lot of other stuff for $100Well Kinect already has the IR laser and camera and much of the R+D costs has probably been paid back by the success of Kinect 1.0. If they can launch with say a 16MP sensor they ought to do well if they can do some kind of zoom and target the laser towards the eye.
mate I dont think even top quality $10000 videocameras do this, perhaps the stuff on moviesets is capable.
also when youre zoomed in like you will be, what happens when the person moves around do their dancing.
the only way today is something attached to the head, like a pair of glasses.