The principles of stereoscopy are not new. In fact, they were known even before photography was invented. Charles Wheatstone produced some of the first known stereoscopic drawings of simple objects back in 1832. With the discovery of photography a few years later, stereo images quickly became a novelty of the Victorian era. Since that time, numerous techniques have been invented to create and display stereo images.
Depth is produced primarily from the display of an object from two slightly different perspectives.
These perspectives correspond to the views from the left and right eyes. There are an almost unlimited number of ways to produce and view stereo images. Four techniques in particular are commonly used in conjunction with computers to visualize 3D models. No specialized display systems are required. The second technique uses polarized light to separate the views intended for each eye.