Refraction of light

Light can travel through different materials or objects. The direction at which it travels can change; the changing or bending of the travel of light is known as refraction.

Refraction of light occurs when light is bent as it travels from a less dense medium to an optically denser medium.

Diagram

An example of light refraction is viewing objects in a pond or water. Light rays from the bottom of the water bend when they move from water into air.

This makes the bottom of the water seem closer than they actually appear.