Here is a most unusual explanation of rods, cones and night vision as performed by the Blue Man Group.
http://www.youtube.com/watch?v=W-yLfm5HsHc [1]
Enjoy. Kevin Paxson - PKV
Links:
[1] http://www.youtube.com/watch?v=W-yLfm5HsHc
[2] http://www.aavso.org/forums/variable-star-observing/visual-observing