Polarization Light Polarization filter
 Polarization of light is useful, after it has been filtered. A filter will separate light with one type of polarization from other types. The filter works much like trying to put a playing card through a comb - only if the card is turned the right direction will it fit. Light that is turned a different way will be blocked by the filter. Glasses that have different polarization filters for each eye can separate light meant for the left eye and for the right eye. This is a common way to make 3D movies and 3D television.