The amount of reflected light actually depends on the angle of incidence of the incoming light. For example, when looking at the surface of a lake from the shore, much of the light is reflected and it is easy to see reflections of the surrounding environment on the surface. However, when floating on a boat on the surface of the lake and looking straight down, there is less reflection and it is easier to see what lies below the surface. This effect is described by the Fresnel equations (after Augustin-Jean Fresnel).
The Fresnel equations describe the amount of light that is reflected as a function of the angle of incidence, the polarization of the light, and the ratio of the indices of refraction. If we ignore the polarization, ...
