Eye and Light at the Explortorium: Jan. 12, 2008

To show pupil:
get a maglight, mirror, and bug box top (lens)
put lens on mirror, then look through lens at mirror
can see pupil!

Iris has more nerves than most other places in the body! That's why it hurts to go from a dark room to a bright room really quickly.

poke a hole at the bottom of a film can, look through it, cover the other eye, and then take it away. It wasn't blurry with the film can, but when you take it away, it IS blurry!

lens is only for fine tuning - pupil does the most focusing! And the smaller the hole, the more focused it is, but the dimmer it is.

Look at your thumb really close up, then look far away, keep doing that and let someone watch. smaller pupils when looking closer, bigger when far away.
(works best with light eyes, maybe can use microscope camera to show one person on LCD projector)

also can do math to find the size of blind spot

mix colors of light, talk about cones

NEI health information for interactive diagram of eye

http://www.exploratorium.edu/snacks/colored_shadows.html

black and white disk on power drill, what will you see? (Only works at certain speeds)
www.exploratorium.edu/snacks/benhams_disk.html
http://faculty.washington.edu/chudler/benham.html
can have kids make their own! do half white and half black and make them draw their own

www.michaelbach.de/ot
for lots of iilusions!