The phenomenon where light changes direction as it passes from one medium to another is known as what?

The phenomenon where light changes direction as it passes from one medium to another is known as refraction. This occurs due to the change in speed of light as it moves between materials with different densities. For instance, when light travels from air into water, it slows down and bends at the interface, causing its direction to change. This bending effect can be observed in various scenarios, such as when using lenses in glasses or cameras, where refraction is utilized to focus or disperse light for clearer images.

Understanding refraction is crucial in optics, as it underpins the behavior of lenses and optical instruments. In comparison, reflection involves light bouncing off a surface, dispersion refers to the separation of light into its component colors (like rainbows), and interference involves the interaction of light waves where they can amplify or diminish each other.