Polarized 3D glasses create the illusion of three-dimensional images by restricting the light that reaches each eye, an example of stereoscopy which exploits the polarization of light.

While watching a stereoscopic film, two images are projected superimposed on the same screen through different polarizing filters. The audience wears polarized 3D glasses that also contain a couple of different polarizing filters. As each filter passes only that light which is similarly polarized and blocks light polarized in the opposite direction, each eye sees a different image. This is used to produce a three dimensional effect by projecting the same scene in both eyes, but using a slightly different perspectives. Since it is not involved the monitoring of the head, multiple people can view the stereoscopic images at the same time.