Extremely rare glass Stereoview manufactured by Drs. Carl W. Lange Sr and Jr
in 1947. This came from the estate of a optometrist in Nashville. I've found
little reference for the Stereotest other than that mentioned in Jrs obituary
which states:

Carl was a fellow in the Eye Research Foundation; President of the St. Louis
Optometric Society; Fellow in the American Academy of Optometry; Chairman of
the Teachers Optometric Conference; President of the Optometric Center; Board
Member of the Missouri Optometric Association; and, Member of the library
Committee of the American Optometric Association. Carl, with his father,
lectured by invitation at many state and local conventions throughout the
country and around the world. They wrote articles for the Professional press on
the Visual Training Technique that Dr. Lange, Sr., developed. The “Lange
Coordinator” was manufactured in Chicago, Illinois and sold all over the United
States and in some foreign countries.

This is a glass slide like stereoview which measures a hair over 8 x 3.5
inches. Very good condition with some wear to tape edging and some spotting
under glass. It appears hand made so I am unsure if this was a slide
manufactured in Chicago or rather a proto type. Manufacture and copyright info
on back. This is slide is Color Fusion Filter "C". Fascinating piece.