Retroreflector
（重定向自Retroreflection）
![](/Images/godic/202502/07/Corner-Cube4207.jpg")
![Working principle of a corner reflector](/Images/godic/202502/07/Corner_reflector.svg4207.png")
![Comparison of the effect of corner (1) and spherical (2) retroreflectors on three light rays. Reflective surfaces are drawn in dark blue.](/Images/godic/202502/07/Comparison_of_retroreflectors.svg4207.png")
![Eyeshine from retroreflectors of the transparent sphere type is clearly visible in this cat's eyes](/Images/godic/202502/07/Eyeshine-BW-cat4208.jpg")
A retroreflector (sometimes called a retroflector or cataphote) is a device or surface that reflects light back to its source with a minimum of scattering. In a retroreflector an electromagnetic wavefront is reflected back along a vector that is parallel to but opposite in direction from the wave's source. The angle of incidence at which the device or surface reflects light in this way is greater than zero, unlike a planar mirror, which does this only if the mirror is exactly perpendicular to the wave front, having a zero angle of incidence.