Seems like a good tutorial! The example video is shot during daytime, though.

jcims · on May 15, 2017

Good point. Night time with glasses and reflections could be a mess.

Might actually be easier with a near IR camera and a couple small LEDs for illumination, as I believe the retina is much more reflective in that range.

gaius · on May 15, 2017

A friend of mine built one of these 5 years ago with an iPhone and on that hardware the darkness problem was insurmountable.