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In 1922, a patent was filed for the first projection lensmeter, which has a similar system to the standard lensmeter pictured above, but projects the measuring target onto a screen eliminating the need for correction of the observer's
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One of five comprehensive instructional videos derived from the original Flash animation on the use of the Topcon lensmeter (vertometer). Produced by Dr Suzane
Vassallo with La Trobe University. These videos are also available
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produced the photographometer, an instrument designed to measure the intensity of photogenic rays; and in 1849 he brought out the focimeter, for securing a perfect focus in photographic portraiture. In 1876,
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in the instrument itself and reducing the requirement to peer down a small telescope into the instrument. Despite these advantages the above design is still predominant in the optical world.
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182:, and is often capable of marking the lens center and various other measurements critical to proper performance of the lens. It may also be used prior to an
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to measure the back or front vertex power of a spectacle lens and verify the correct prescription in a pair of
178:: sphere, cylinder, axis, add, and in some cases, prism. The lensmeter is also used to check the accuracy of
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of a convex lens. Troppman went a step further in 1912, introducing the first direct measuring instrument.
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to obtain the last prescription the patient was given, in order to expedite the subsequent examination.
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The parameters appraised by a lensmeter are the values specified by an
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Millodot: Dictionary of
Optometry & Visual Science, 7th edition
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Ophthalmic instrument mainly used by optometrists and opticians
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lensometer (sometimes even known as focimeter or vertometer)
304:"Ophthalmology Glossary on Carl Zeiss Vision GmbH website"
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introduced a phakometer which was a similar set up to an
351:at George Eastman House Inc.: 1–2. Archived from
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207:which could measure the power and find the
71:A simple lensmeter cross sectional view.
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163:, if a special lens support is used.
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126:– Power drum (+20 and -20 Diopters)
349:International Museum of Photography
143:, is an optical instrument used in
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61:A Lensmeter in an Optical shop
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254:Corrective lens components
121:– Angle adjustment lever
332:, eds. (February 1952).
147:. It is mainly used by
347:(2). Rochester, N.Y.:
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76:– Adjustable eyepiece
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432:Measuring instruments
107:– Illuminated target
89:– Keplerian telescope
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427:Ophthalmic equipment
393:accessed 20 Jan 2009
279:"Vertometer. (n.d.)"
259:Abbe refractometer
180:progressive lenses
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131:– Prism scale knob
103:– Standard lens
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407:Lensometry basics
358:on March 12, 2013
326:Newhall, Beaumont
322:Solbert, Oscar N.
174:on the patient's
85:– Objective lens
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16:(Redirected from
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334:"The Focimeter"
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310:on 12 May 2008.
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201:Hermann Snellen
196:Antoine Claudet
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184:eye examination
168:ophthalmologist
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112:– Light source
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98:– Unknown lens
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94:– Lens holder
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386:. Retrieved
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378:"Focimeters"
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353:the original
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287:. Retrieved
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176:prescription
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149:optometrists
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116:– Collimator
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172:optometrist
50:Archive.org
42:Wikiversity
421:Categories
388:2010-01-30
289:2015-01-04
265:References
229:Lens clock
157:eyeglasses
80:– Reticle
18:Vertometer
244:Focometer
194:In 1848,
153:opticians
137:lensmeter
362:June 16,
223:See also
239:Diopter
190:History
46:Youtube
285:. 2009
356:(PDF)
341:Image
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364:2014
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
