Eye Experiment

     Stare at the dot at the bottom right of the stars on the flag below for 30 seconds.  Then quickly cover it up with white paper and you should see the red, white, and blue flag. 

     This reason this experiment works is as follows.  The cones in the back of the eye are paired together: green and red, yellow and blue, and black and white.  These cones compete to send messages to the brain.  As you look at the flag of yellow, green, and black for a little while, the yellow, green, and black cones get overactive.  When you stop loking at that flag, the other colors try to get back into balance but bounce too far at first.  That is why you see the red, white, and blue flag.