Here's something fun to play with. I ran across an article about motion induced blindness.

It's where your mind plays tricks on you by having you pay more attention to the moving parts, which makes your brain not see the stationary parts.  It's fun to play with. Just think of the hours of enjoyment you can have in the office.

Motion Induced Blindness from Wikipedia.com

To read more on Motion Induced Blindness click here for the Wikipedia.org link.