Holmes’ stereoscopic viewer

Optic device for viewing three-dimensional images. Based on research on binocular perception, it was invented in 1861 by Oliver W. Holmes, to view photographs taken with a stereoscopic camera. Early studies, attributed to the astronomer Johannes Kepler, appeared in the 16th century, but it was not until the 19th century when the optical instruments based on these studies materialized. The system was used by the Basque scientist Ramon i Cajal to explain his work on neurons, and by the Catalan painter Salvador Dali to show some of his paintings.

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