Snellen test type

block letters used in testing visual acuity, so designed that the whole letter subtends, at the appropriate distance, a visual angle usually of 5 minutes, and each component part subtends an angle of 1 minute. See also Snellen chart, under chart.

Two Snellen test types.


Medical dictionary. 2011.

Look at other dictionaries:

  • 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

  • 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

  • Test, visual acuity — This test measures how well you see at various distances. It is the familiar eye chart test. The eye chart itself the usual one is called Snellen s chart is imprinted with block letters that line by line decrease in size, corresponding to the… …   Medical dictionary

  • Test, eye chart — This test measures how well you see at various distances. The eye chart itself the usual one is called 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 …   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 chart etc. — Snel·len chart, etc. (snelґən) [Hermann Snellen, Dutch ophthalmologist, 1834–1908] see under chart, eye, sign, test, and test type …   Medical dictionary

  • test types — Letters of various sizes used to test visual acuity. Jaeger t. type of different sizes used for testing the acuity of near vision. point system t. a near vision test chart …   Medical dictionary

  • Acuity test, visual — This test measures how well you see at various distances. It is the familiar eye chart test. The eye chart itself the usual one is called Snellen s chart is imprinted with block letters that line by line decrease in size, corresponding to the… …   Medical dictionary

  • Visual acuity test — This test measures how well you see at various distances. It is the familiar eye chart test. The eye chart itself the usual one is called Snellen s chart is imprinted with block letters that line by line decrease in size, corresponding to the… …   Medical dictionary

  • Eye chart test — This test measures how well you see at various distances. The eye chart itself the usual one is called 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 …   Medical dictionary


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