Wolfram Demonstrations Projecthttp://demonstrations.wolfram.com/An Open Resource of Interactive Mathematica VisualizationsCopyright 2009 Wolfram Demonstrations Project & ContributorsLight Refraction with a Waterdrophttp://demonstrations.wolfram.com/LightRefractionWithAWaterdrop/]]>http://demonstrations.wolfram.com/LightRefractionWithAWaterdrop/Designing Optical Systemshttp://demonstrations.wolfram.com/DesigningOpticalSystems/]]>http://demonstrations.wolfram.com/DesigningOpticalSystems/