Fincham coincidence optometer

Catalogue Number: 629
Fincham coincidence optometer
Category: Equipment
Sub-Category: Optometer
Designer/inventor: FINCHAM Edgar F
Year Of Publication/Manufacture: Originally made 1935.
Time Period: 1900 to 1939
Place Of Publication/Manufacture: England
Publisher/Manufacturer: Taylor, Taylor and Hobson Ltd
Description Of Item: Brown metal optometer with a meridian and a power dial. patient headrest and examiner eye piece. A table top ophthalmic instrument devised to measure refractive error. It uses image doubling of a line object so that precise determination of the refractive error could be made by vernier alignment of the doubled line. The line object can be rotated to determine the principal meridian of astigmatism. Inscribed by the manufacturer with 'Made exclusively by Taylor, Taylor and Hobson Ltd, Model No 68 (104/94). According to The British College of Optometrists Museum it was made for Clement Clarke and Co Ltd, a London firm of optical instrument suppliers.
Historical Significance: The instrument was developed in 1935. It was exhibited in 1935 at the 25th exhibition of instruments of the Physical Society (See Inst Physics online archive http://gita.grainger.uiuc.edu/iop/JournalArticle.asp?issn=0034-4885&volume=3&issue=1&artnum=323&lang=) and Fincham published the principles of the instrument in 1937. It is an example of ingenuity to find better ways of measuring refractive errors but the instrument was never widely used. The Victorian College of Optometry probably bought this instrument in the 1960s for teaching purposes but it was never used clinically. See Fincham EF. The coincidence optometer. Proc Physical Soc, 1937; 49, (5): 456-468 and R E Reason The development of the Fincham coincidence optometer Proc. Phys. Soc. 1937; 49: 469-478 doi:10.1088/0959-5309/49/5/304. The optical principles are described in Smith G and Atchison DA. The eye and visual optical instruments Cambridge Press 1996. EF Fincham (1893 - 1963) FIntPhys FSMC FBOA taught in the optometry course at the Northampton Polytechnic in London, later City University. He was the inventor of a number instruments including the Fincham ophthalmo-retinoscope (see cat No 1124), the Fincham Plastic Artifical Eye Fitting Set, the Fincham photo-retinoscope, Fincham Sutcliffe screening scotometer, the Electronic field-plotting chart and the Fincham combined corneal microscope and slit lamp. He also published a number of scholarly papers of accommodation and other subjects. See obituary Br J Ophthalmol 1964; 48: 120
How Acquired: Purchased by Victorian College of Optometry
Condition: Good. One forehead rest is missing. Power lead lacks a plug
Location: Archive room. East wall Unit 4 Cupboard

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