Which phenomenon describes the deflection of light when passing through different mediums?

The phenomenon that describes the deflection of light as it passes through different mediums is known as refraction. This occurs when light travels from one medium to another, such as from air into water, causing it to change speed and direction. The bending of light is governed by Snell's Law, which quantifies the relationship between the angle of incidence and the angle of refraction based on the indices of refraction of the two mediums involved.

Refraction is crucial in many applications, such as in lenses used in glasses and cameras, where it allows for the focusing of light to create clear images. Understanding this concept is essential for anyone involved in optics or fields related to light, such as photography, vision science, and even various engineering applications.

The other options relate to different light behaviors: reflection refers to the bouncing of light off surfaces, diffraction involves the bending and spreading of waves around obstacles, and scattering denotes the redirection of light in multiple directions due to particles in a medium. While all these phenomena involve light, only refraction specifically deals with the change in direction as light passes between different media.