Refraction
Refraction is the change in the direction of propagation of a light beam at interfaces. If a light beam from one medium hits another medium with a different refractive index, the beam is deflected or refracted. In addition, part of the light is reflected at the interface. At the interface, a fraction is separated into a fractional and a reflected part. The medium with the higher refractive index is called the optically denser one.
