Image formation is the result of the light of a luminous object being refracted through a double convex lens to form an image, or identical representation, of the object. Refraction is a wave phenomenon light exhibits because it is an electromagnetic wave and it occurs whenever light enters a medium that can modify its speed. Another factor that impacts image formation is the index of refraction, which leads to chromatic dispersion.

Refraction is always accompanied by a change in the direction of travel, and the immediate consequence of light penetrating a lens is that it is bent to an extent described by Snell's law, which is derived from the Fresnel equations, and expressed as follows: n/n = sint/sint, where n is a dimensionless unit called the index of refraction and is defined as the speed of light in vacuum divided by the speed of light...