Which property of light is described by the change in speed as it travels through different media?

The property of light that is described by the change in speed as it travels through different media is refraction. Refraction occurs because light travels at different speeds in different materials due to variations in density and optical properties. When light passes from one medium (like air) into another (like water or glass), its speed changes, resulting in a bending or change in direction of the light rays. This bending is responsible for various optical phenomena, such as the appearance of objects submerged in water seeming to be at a different position.

Understanding refraction is essential in optics, especially in the design of lenses and other optical instruments, as it determines how light will behave when entering or exiting various mediums. This principle is foundational in explaining various optical effects and is critical in the field of optometry and vision care. In contrast, wavelength, frequency, and intensity are important aspects of light but they do not directly describe the change in speed associated with different media.