Main Page | See live article | Alphabetical index Angle of refraction is the angle between the beam refracted at the boundary between two media of different refractive indices and the normal (line perpendicular to the surface at the point of the incidence). Note: The beam can be formed by any wave: optical, acoustical, microwave, X-ray etc. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.