Refraction is the bending of light when light travels from one material into another, based on a change of speed, changing the light’s direction. The amount of bending is based on the density of the materials( representing how fast the light travels through the material ) and is called “index of refraction”. Refraction can be seen in the real world by putting a pen into a glass of water, when swimming, looking on a glass statue, in gems and so on.