From Joop Gerritse:

Re: What is consciousness? Study aims to settle debate (May 20): It seems that almost nobody realizes that you cannot see anything and remain invisible. Not, at least, if we’re talking about true vision. In that case, you have to diffract, focus, and absorb light, and you should be visible, maybe in infrared, maybe in X-rays... So, direct your camera towards the ceiling, and check if you see two “eyes” somewhere... I don’t think that you will find anything, though.

Joop Gerritse
D-47546 Kalkar-Wissel
Germany
http://www.jjge.nl