Title Babe Ruth & Tom Mix Keystone Eye Comfort stereoscopic testing view 1920s
Seller ID 1477379
7 x 3 1/2" curved stereoview used in conjunction with an eye exam device. Writing on back hard to scan, but here is all of it: "The Keystone Eye Comfort And Depth Perception Series - For the Development of Comfortable Vision and a Zhigh Degree of Depth Perception. / E C 109-33290 Fusing the two upper images requires 14 prism diopters divergence (prism B) / Fusing the two lower images requires 19 prism diopters divergence (prism B) / Keystone View Company Meadville Penna. Printed in U S A."
Dimensions given, if any, are approximate. Condition as shown. Defects not visible in scan[s] are described. Item is complete as issued unless otherwise stated. NO facsimiles, copies, reprints or reproductions unless specifically stated in description above. Pictures show actual item, never a stock image.