FITS-U eyeglasses (fitting set)

Historical Significance: The trial finger piece set was an optician's tool to fit patients with an appropriate pince-nez. This set was probably made by the American Optical Company since the company is known to have made such sets using the brand name FITS-U. See http://pincenez1.blogspot.com/2008/03/trial-fingerpiece-set.html. The "Fits-U" trial finger piece sets were made from 1903 to about 1930 by the American Optical in Southbridge, Massachusetts. Smaller makers such as Perfex and Shur-On also made pince-nez fitting sets. There are three different factors determining fit of pince-nez: 1) interpupillary distance, 2) height of the bridge, and 3) inclination of the crest of the bridge. These parameters are designated in the three digit number on each lens, The first digit of the three digit number indicates pupillary distance in the unit of 1/16th inch, the second digit indicates the height of the bridge (also in 1/16 inch units) and the third digit indicates the inclination of the bridge beyond the plane of the lenses. See Cat Nos 1729, 1730 and 2035 for other examples.