Refraction experiment. Shine a light from a ray-box into a semicircular glass block and observe refraction and internal reflection, just like the traditional experiment.

Nice animation of waves being refracted. By Fu-Kwun Hwang

Fish-eye view. Nice! Refraction and thus the image changes as you move the object. By Fu-Kwun Hwang.

Fermat Principle. This java applet let you visualize how refraction is caused by light traveling the path of least travel time". ByFu-Kwun Hwang.

Mirages. Look at results from Yahoo search.

Tutorial by Glenbrook High School.

Tutorial by Clarence Bakken.