What is the bending of light as it travels from one medium into another called?

The term that describes the bending of light as it travels from one medium into another is refraction. This phenomenon occurs due to a change in the speed of light as it enters a medium with a different density. When light moves from air into water, for instance, it slows down and bends towards the normal line, which is an imaginary line perpendicular to the boundary between the two mediums. This bending effect is responsible for various optical illusions and plays a crucial role in the functioning of lenses in glasses, cameras, and other optical devices.

In contrast, diffraction pertains to the spreading of waves when they encounter an obstacle or pass through a narrow opening, while reflection is the bouncing back of light when it hits a surface. Absorption refers to the process by which a material takes in light energy, converting it to other forms of energy, rather than allowing it to pass through or bend. Understanding refraction is essential for grasping the principles behind how lenses manipulate light to focus or disperse images.