Heat haze is a phenomenon caused by the diffraction and refraction of light waves as they pass through layers of air of varying temperature. This results in a shimmering, wavering effect that can distort the appearance of objects in the distance. Synonyms for heat haze include mirage, shimmer, distortion, blurry air, and atmospheric quiver. These words describe the same effect of distorted vision caused by hot air rising from the ground or the surface of a road on a hot day. Whether one is in the desert or on a city sidewalk, a heat haze can be a visually fascinating experience to observe.