The above web page include two animation: refraction/reflection and thin lens refraction.
However, for the refraction/reflection part. I would suggest you to check out [url=http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=347.0]Intensity of reflected s-wave/p-wave[/url].


When light enter into another media, reflection will always occurs.
The animation only show either reflection or refraction. It might introduce mis-concept about the light.