Brewster lenticular stereoscope, Museo nazionale della scienza e della tecnologia Leonardo da Vinci

David Brewster FRS invented the first portable 3-D viewing device in 1849 – using prisms and lenses rather than mirrors, the lenticular or refracting stereoscope was a more compact device than Wheatstone’s reflecting stereoscope (1838). Its portability and ease of use meant that it gained popularity over Wheatstone’s design.