CK-12 Foundation
Ck 12: Plix: Color: Light in a Prism
[Free Registration/Login Required] Explore how light is refracted when visible light enters, passes through, and exits the prism by moving the red dot to adjust the angle of white light shining on the prism.
Optical Society
Optical Society of America: Optics for Kids: Lose a Glass in a Glass
This is an activity that should only be done outdoors or in a well-ventilated area, with adult supervision, as it involves paint thinner. It demonstrates the concept of the index of refraction for different materials, in this case that...
Optical Society
Optical Society of America: Optics for Kids: Bending Light
An experiment using a water lens that demonstrates how the eye sees an image. Accompanied by an explanation of what's happening, and a link to an article on refraction.
Walter Fendt
Walter Fendt: Reflection and Refraction of Light
Defines the refraction of light and provides an applet for investigating it.
Optical Society
Optical Society of America: Optics for Kids: Blue Sky Red Sunset
An experiment where light is shone through a bottle of water, and then milk added, to see how this affects the path the light takes (with links to articles on reflection and refraction that explain what is happening).