Keystone Ophthalmic Telebinocular

Historical Significance: This unit was used for decades by school nurses at The Peninsula School, Mt Eliza, to screen the vision of incoming Year 7 students. It was decommissioned in 2010 as the company that had calibrated and serviced the machine felt that it was no longer worth maintaining.US Patent 2,557,608 was granted on June 19, 1951 to Gifford M Mast & Wright K Gannett and assigned to the Keystone View Company. (See instruction manual Cat No 2016 for details of operation including its use for binocular refraction). The Keystone View Company was founded in 1895 by B L Singley, a typewriter salesman, with an interest in stereographic photography. It became a major distributor of stereographic images, located in Meadville, Pennsylvania. From 1892 to 1963 Keystone produced and distributed both educational and comic/sentimental stereoviews, and stereoscopes. By 1905 it was the world's largest stereographic company. By 1935 it had photographers around the world and a stock of 2 million stereo negatives. Keystone's Stereo-ophthalmic Department was formed in 1932 to meet the needs of eye specialists, safety and efficiency engineers and psychologists who needed stereoscopic vision tests. In 1963 Department A (stereoviews sold to individual families) and the Education Departments were closed down, but Keystone continued to manufacture eye-training stereographic products as a subsidiary of Mast Development Company. In 1972 Mast closed the Meadville manufacturing site.