Before the television -- and before the MagicEye and the Viewmaster -- Victorians had the stereoscope. A stereograph picture was made of two photographs, pasted side by side, which had been taken from two nearly, but not exactly, the same perspective. The stereoscopic viewer brought the eye to focus on the two pictures as one, aping natural binocular vision which presents objects to our brain in three dimensions.
An artist can draw an object as he sees it, looking at it only with his right eye. Then he can draw a second view of the same object as he sees it with his left eye. It will not be hard to draw a cube or an octahedron in this way ; indeed, the first stereoscopic figures were pairs of outlines, right and left, of solid bodies, thus drawn. But the minute details of a portrait, a group, or a landscape, all so nearly alike to the two eyes, yet not identical in each picture of our natural double view, would defy any human skill to reproduce them exactly. And just here comes in the photograph to meet the difficulty. A first picture of an object is taken,--then the instrument is moved a couple of inches or a little more, the distance between the human eyes, and a second picture is taken. Better than this, two pictures are taken at once in a double camera.(From Oliver Wendell Holmes' Atlantic Monthly article in 1859.)
Stereographs brought the exotic and remote into the home. If one traveled, souvenir pictures could be bought at bookstores and kiosks. Natural disasters, foreign landmarks, strange cultures became immediate experiences through this precursor of the newsreel. The above view of Japan is an example of the handcoloured stereograph.
It entertained, with scenes of dramatic characters. This is a model dressed as the comic Lord Dundreary from the hugely popular play Our American Cousin (1858).
It also catered to the adult male viewer.
The stereoscope was even more popular in middle-class Victorian homes than the parlour piano. It was an educational tool, a source of entertainment, a window on the larger world. One historian estimates the number of sterescopic photos made between 1860 and 1890 as upwards of 400 million (see Michael J. Murphy in St. James's Encyclopedia of Pop Culture online).
Some websites where you can learn more about the stereoscope and stereographic views are: Michael Murphy's online article; the Central Pacific Railroad Photograph History Museum link; Rick Saunders' website; and the Library of Congress online collection.