Refraction and Lenses

Our Refraction and Lenses unit represents an effort to apply optics principles to an understanding of refraction, Snell's law, total internal reflection, dispersion, mirage formation, converging and diverging lenses, and image formation. The set of Video Tutorials below describe all sorts of applications of refraction principles to the analysis of physical situations.

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What is Refraction?

Optical Density, Light Speed, and n

​The Direction of Bending

​Snell's Law of Refraction

​Snell's Law and Ray Tracing

​Determining the Index of Refraction

Total Internal Reflection

​The Critical Angle

​Light Dispersion and Rainbows

​Refraction in a Non-Uniform Medium

​Refraction by Lenses

​Lenses and Image Formation

​Converging Lenses: Ray Diagrams

​Converging Lenses: Object-Image Relations

​Diverging Lenses: Ray Diagrams and Object-Image Relations

​Mathematics of Lenses

​Refraction and the Eye

​Farsightedness and Nearsightedness