What causes the refraction of light?

Refraction of light:

1. The change in the direction of a light ray on passing from one medium to another is called refraction.
2. The bending of light takes place due to the difference in the optical densities of the two media.
3. The material that moves energy or light from one substance towards another, from one location to another, or from one surface to another is called medium.

The refraction of light is shown in the diagram given below.

Causes of refraction of light:

The cause of the refraction of light is that light travels at different speeds in different media. This change in the speed of light when it moves from one medium to another causes it to bend.

1. When the light goes from air into water, it bends towards normal because there is a reduction in its speed.
2. When the light goes from water to air, it bends away from normal because there is an increase in the speed of light.