I’ve watched Brian Tong’s video review and it brought up a couple more questions
Is eye tracking the right input form?
I suspect that a lot of what we do with our eyes is unconscious, and Brian Tong mentioned that you can start looking ahead of where you’re tapping.
This seems very reasonable to me, and why mouse and keyboard are so usable, because they allow us to use the tactility of our hands while scanning ahead or multitasking with our eyes.
Spatial interfaces will feel hollow without tactility
Having to use our eyes as the “mouse” might make it so we have to operate more slowly. This could be good or bad, or at least uncomfortable.