Refractometer of Berth and Neuman
 Catalogue Number: 1980 Refractometer of Berth and Neuman Category: Equipment Sub-Category: Optometer Designer/inventor: Schmid-Rimpler Year Of Publication/Manufacture: 1921 Time Period: 1900 to 1939 Place Of Publication/Manufacture: Jena Publisher/Manufacturer: Berth and Neuman Description Of Item: Instrument for the objective measurement of refractive error, black enamelled and polished metal. L-shaped table top base, chin and forehead rest for the patient, rotatable electric light source housing, with degree scale, attached to a moveble metal support bar with a dioptre scale. Marked 'Jena' within a triangle and the serial number No 0602 Historical Significance: This is the first refractometer manufactured serially. The design was patented in 1921. It is based on the principle devised by Schmidt-Rimler who in 1877 projected a grid target on to the macula that could be observed ophthalmoscopically and focussed by adjusting the optics of the instrument. The idea was first proposed by Donders. Lack of strong enough illumination limited the usefulness of the idea, which had to wait the invention of the electric light. References (1) Hirschberg's History of Ophthalmology Vol II (Part 2) Optical instruments Author: T v,Haugwitz See Page A31 (2) Berth H. Augenrefractometer. Z Ophthalmol Optik v13 p 18 (3) Krumer R. Historisch-Krtiisches zum refractometer von Berth and Neuman (Jena) Klin Monblat Augenheilk v69(2) p 93. NOTE: COPIES OF THE LATTER TWO PAPERS ARE FILED IN ARCHIVE OFFICE PAMPHLETS AND EPHEMERA FILE DRAWER 5 Condition: Good but electric cable is missing Location: Archive room. East wall Unit 4 Cupboard |