It is supposed that the latter serves monocular, the other the binocular vision, most birds being able to converge their eyes upon one spot.
Sir Charles Wheatstone discovered its principle and applied it as early as 1838 to the construction of a cumbrous but effective instrument, in which the binocular pictures were made to combine by means of mirrors.
The first binocular magnifying glass or simple microscope (German, Lupe) was devised by J.
In light there are a series of papers on the eye, on the physiology of vision, on binocular vision, including the invention of one of the popular scientific instruments, the stereoscope, and on colour.
Binocular Instrument >>
Regnault, a paper on binocular vision.