This applet shows you how light is refracted when it travels from one medium to another medium of a different refractive index.
Snell's Law: ni sin θi = nr sin θr
where ni = refractive index of the first medium,
θi = angle of incidence,
nr = refractive index of the second medium,
θr = angle of refraction.
When light travels from one medium to another medium of lower refractive index
and the angle of incidence is greater than a certain critical angle, total internal reflection occurs.
Refractive Indices of Common Materials:
Right-click here to download this page and the Java Class File.