The next Kinect is supposed to be able to detect eye movement. I don't think it would be too hard to implement something that would prompt for a sequence of eye

The next Kinect is supposed to be able to detect eye movement. I don't think it would be too hard to implement something that would prompt for a sequence of eye movements after pressing the single button switched described by OP. I don't know if this would take care of both use cases, but I think it would take care of the first.