Snellen, Hermann

Snellen, Hermann
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b. 18 February 1834 Zeist, near Utrecht, the Netherlands
d. 18 January 1908 Utrecht, the Netherlands
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Dutch ophthalmologist who developed scientifically based visual testing types.
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Snellen took his degree in medicine at Utrecht in 1857, and after continued study was appointed Lecturer in Ophthalmology and Surgeon to the Hospital for Diseases of the Eye. In 1877 he succeeded Franciscus Cornelius Donders, an outstanding figure in the development of the understanding of the optics and physiology of vision, as Professor. He held this post until 1899 when he was succeeded by his son.
Although involved in virtually all aspects of the speciality, he particularly laid the basis for the scientific recording of visual acuity with the publication of his Optotypes in 1862. Optotypes were based on the concept of an average standard of vision permitting the discrimination of separate objects which subtended an angle of one minute of arc on the retina. While the concept does not take into account aspects of vision such as perception, it has stood the test of time in terms of practicality, even when abstract figures such as Landolt's rings replace the lines of single letters of the original.
Snellen originated many other advances of a surgical nature, his procedure for eyelid deformity is still practised, and he developed the use of glass in the manufacture of artificial eyes.
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Principal Honours and Distinctions
Honorary Member and Bowman Lecturer, Ophthalmological Society, UK.
Bibliography
1862, Optotypes/Ad visum determinandum, Utrecht. 1874, Des Functionem Sprungen.
1862, Scala tipografica per mesurare il visus.
Numerous papers in Graefes Archiv für Augenkinde and the Graefe-Saemisch Handbuch.
Further Reading
S.Duke-Elder, 1969, System of Ophthalmology, London. 1973, The Foundations of Ophthalmology, Vol. 5.
MG

Biographical history of technology. - Taylor & Francis e-Librar. . 2005.

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  • Hermann Snellen — H. Snellen Sr. Herman Snellen Sr (* 19. Februar 1834 in Zeist; † 18. Januar 1908 in Utrecht) war ein niederländischer Augenarzt und Hochschullehrer der Augenheilkunde in Utrecht. Er ist vor allem wegen der Erfindung der Sehprobentafeln bekannt… …   Deutsch Wikipedia

  • Snellen chart — Snel·len chart snel ən n the chart used in the Snellen test with black letters of various sizes against a white background Snellen Hermann (1834 1908) Dutch ophthalmologist. Snellen was director of an eye clinic at Utrecht. In 1862 he introduced… …   Medical dictionary

  • Snellen — Hermann, Dutch ophthalmologist, 1834–1908. See S. sign, S. test types …   Medical dictionary

  • Snellen's chart — The familiar eye chart used to measure how well you see at various distances. Snellen s chart is imprinted with block letters that line by line decrease in size, corresponding to the distance at which that line of letters is normally visible. The …   Medical dictionary

  • Snellen's test type — The letters on the familiar eye chart used to measure how well you see at various distances. The eye chart, known as Snellen s chart, is imprinted with block letters that line by line decrease in size, corresponding to the distance at which that… …   Medical dictionary

  • Hermann Snellen — Herman Snellen (February 19, 1834, Zeist January 18, 1908) was a Dutch ophthalmologist who introduced the Snellen chart to study visual acuity (1862). He took over directorship of the Netherlands Hospital for Eye Patients after Dr. Frans Cornelis …   Wikipedia

  • Hermann Snellen — noun Dutch ophthalmologist who introduced the Snellen chart to study visual acuity (1834 1908) • Syn: ↑Snellen • Instance Hypernyms: ↑ophthalmologist, ↑eye doctor, ↑oculist …   Useful english dictionary

  • Snellen — noun Dutch ophthalmologist who introduced the Snellen chart to study visual acuity (1834 1908) • Syn: ↑Hermann Snellen • Instance Hypernyms: ↑ophthalmologist, ↑eye doctor, ↑oculist …   Useful english dictionary

  • Snellen chart etc. — Snel·len chart, etc. (snelґən) [Hermann Snellen, Dutch ophthalmologist, 1834–1908] see under chart, eye, sign, test, and test type …   Medical dictionary

  • Snellen-Sehproben — Snẹllen Se̱hproben [nach dem niederl. Ophthalmologen Hermann Snellen, 1834 bis 1908]: Tafeln mit Buchstaben, Zahlen und hakenförmigen Zeichen in verschiedener Größe zur Prüfung der Sehschärfe …   Das Wörterbuch medizinischer Fachausdrücke

  • Chart, Snellen's — The familiar eye chart used to measure how well you see at various distances. Snellen s chart is imprinted with block letters that line by line decrease in size, corresponding to the distance at which that line of letters is normally visible. The …   Medical dictionary

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