Dr Culbertson's Prisoptometer
 Catalogue Number: 1177 Dr Culbertson's Prisoptometer Category: Equipment Sub-Category: Optometer Designer/inventor: H Culbertson Year Of Publication/Manufacture: c1886 Time Period: 19th C Place Of Publication/Manufacture: Geneva, New York, USA Publisher/Manufacturer: The Geneva Optical Company Description Of Item: Made of cast iron, steel, brass & glass. Imprinted DR CULBERTSON'S PRISOPTOMETER/ GENEVA OPTICAL COMPANY MAKERS, GENEVA, N.Y./ PATENTED SEPT, 21, 1886. Stamped 853 on eyepiece & lens mounting. L: 55cm x W: 21cm Historical Significance: This is an early optometer based on a unique principle. The instrument contains a prism which could be rotated, and was used to view a disc or object circle. The prism caused monocular doubling of the object circle and the separation of the two images varied as the prism rotated, depending on the astigmatism present. The axis of the astigmatism was indicated by the prisoptometer and trial lenses were used to determine the magnitude of the spherical and cylindrical refractive error. See catalogue No 202 and 570 for other examples of the same kind of optometer and further historical information. How Acquired: Donated by Pamela Sutton, honorary archivist Date Acquired: 11.4.2009 Condition: Good Location: Archive room. West wall. Unit 4 Drawer 5 |