Its like a water rain drop... i also think that the light is divided into their colors, so you can see blue green and red, colors, Its cool the effect , sepecial for water and that things .. I guess is that! ~
: The Fresnel Lens
A fresnel lens has unusual properties. It collects light from a point source, and re-directs it in parallel directions. Used "backwards" (capturing the "parallel" rays of the sun, and gathering them to a point source), it is a potent weapon. Used "forwards" (capturing the emitted rays of your monitor), it provides a degree of magnification. This property is used by some cockpit builders to achieve a larger picture than their monitor can display. The lens must be placed a prescribed distance in front of the monitor. Some fresnel users actually claim a certain "depth" to the image not available on a regular monitor, but this depth should not be confused with 3-D perception.
So it is the opposite of reflection( called refraction...)
As shader shot :
