Can you make the dot disappear? Click on the site below, and then explain why the dot disappears (if it does!).
http://www.exploratorium.edu/exhibits/fading_dot/fading_dot.html

From the site below, explain the clues we use for depth perception. (HINT: Use the "Table of Contents" from the book The Joy of Visual Perception, by Peter Kaiser.)
http://www.yorku.ca/eye/thejoy.htm