Introduction:

Refraction is the changing in direction of waves as they go from one medium to another. Refraction of light is `the bending of light rays at the boundary or interface, as they go from one medium to another. The amount the rays bend depends on the optical density of the material. A ray bends toward the normal when going from a less optically dense material to a more optically dense material, and when going from more dense to less dense material, it bends away from the normal. The amount of refraction that occurs is results from the changing speed of light as it goes from air to the medium. This can be explained, because when hitting the boundary, one side of the ray slows down first, while the other side keeps going at a faster speed...