Whittington stereoscope with a variety of slides, made by Theodore Hamblin Ltd., London, W1, England, 1925-1940.

Stereoscopes were handheld devices that enabled the viewer to see a 3D image through the viewfinder. This optical illusion was created by placing two slides of the same subject, drawn from slightly different viewpoints, in the holder. The two images merge to form a 3D view. The stereoscope was first demonstrated to the Royal Society in 1838 by Charles Wheatstone (1802-1875) and became essentially an amusing novelty. Stereoscopic viewers were extremely popular from 1860-1920. They were almost as common in American and European households as the television is today.

This stereoscope was developed by and named after ophthalmologist Theodore Henry Whittington (1887-1983). It helped diagnose sight problems and test the vision of both eyes working together (binocular vision). This example is made of wood, metal and glass. It was manufactured by opticians Theodore Hamblin Limited. It is seen with associated slides (A657813 Pt 1).