National Institutes of Health
National Eye Institute: Optical Illusions
Visit this site for some optical illusions for you to have fun with! Click on the "optical illusions" page in this PDF format for a printable version of these four illusions.
George Eastman Museum
George Eastman House: Create a Zoetrope
A zoetrope, or the "wheel of life," is an early way motion pictures were made. With these easy to follow directions you can create one of your very own using the printable templates.