A Collection of Keystone View Company Third-Dimension Eye-Training Series & Eye-Test Stereoviews
Meadville Pennsyvlania: Keystone View Company. Photography. Group of 31 total images, mounted on card: (14) stereoviews used to test eyesight, directions for use on the reverse of the mounts; & (17) Third-Dimension Eye-Training cards. Approx. 3 1/2" x 7" size; light wear to the mounts; one with corner-surface chipped away;.....