American Optical Phoropter Model 590

Historical Significance: Charles Spencer was the first American to successfully make microscopes in the U.S.A., publishing his first catalogue in 1838. In 1865 he began operating as C. A. Spencer and Sons. In 1873 Spencer and his sons moved from the original shop in Canastota, New York to Geneva, New York. After Charles death in 1881 the business was carried on by his son Herbert, who, after a time moved to Cleveland, Ohio, and then, in 1890, to Buffalo, New York, where the company remained. For a short time, between 1890 and 1895 the company became known as Spencer and Smith. The Spencer Company was incorporated in 1895, using the name Spencer Lens Company up into the 1940's. Spencer was the only microscope manufacturing firm in America until 1849. American Optical was established in 1833 as a small spectacle manufacturing concern in Southbridge, Massachusetts. The company grew rapidly, gradually acquiring additional facilities for manufacturing a range of optical products. In 1935 this expansion lead to its purchasing the Spencer Lens Company of Buffalo, New York. Henry DeZeng had developed a phoropter in 1909 and coined the term 'phoroptor' or 'phoropter'. American Optical Co. bought DeZeng in 1925 and in 1927 introduced Model No. 588, the AO Wellsworth DeZeng Phoroptor. This Model 590 AO phoropter is the third phoropter produced by American Optical (Models in 1927 and 1934, and this one 1948). It was the first phoropter to break away from the DeZeng design. (See Cat No 1062 for an example of a 1920 DeZeng phoropter). Patent numbers stamped on the phoropter suggest a number of people were involved in the development of the model 590 including Ernest Tillyer. The Model 590 was superseded by the AO RxMaster in 1956. See https://en.wikipedia.org/wiki/Phoropter