Caused by the movement of light through a medium with different densities. As a result, the direction of the light changes. Which at the time was light refraction will cause reflection of light simultaneously.
Arising from that light moves through a medium with a different density, as a result, the direction of the light change. At which point the light refraction occurs, it will cause reflection of light up at the same time.
There was a light from the moving through the medium of a different density, as a result of the light changes direction, while a light Deflection occurs, there will be a reflection of the light up simultaneously.