Ishihara Test


Other Known AliasesPseudo-isochromatic plates

DefinitionTest for detecting color blindness using different color dots to outline numbers

Ishihara 9.png

Clinical SignificanceAllows for quick assessment of color blindness using different styles plates (a full test is 38 plates) and even differentiate between different types of color blindness.  Research has proven that a score of 12 out of 14 red/green plates indicates normal color vision with a sensitivity of 97% and a specificity of 100%.

History – Named after Shinobu Ishihara (1879-1963), who developed these while working as a military surgeon for the Japanese army during World War I as a better way of assessing color blindness in troops.  He first published these findings in 1917 in Japan and it was first translated and reviewed in the American Journal of Ophthalmology in June 1918 extolling its usefulness.



  1. Firkin BG and Whitwirth JA.  Dictionary of Medical Eponyms. 2nd ed.  New York, NY; Parthenon Publishing Group. 1996.
  2. Bartolucci S, Forbis P.  Stedman’s Medical Eponyms.  2nd ed.  Baltimore, MD; LWW.  2005.
  3. Yee AJ, Pfiffner P. (2012).  Medical Eponyms (Version 1.4.2) [Mobile Application Software].  Retrieved http://itunes.apple.com.
  4. Whonamedit – dictionary of medical eponyms. http://www.whonamedit.com
  5. Ishihara S.  Tests for Color Blindness.  AJO. 1918;1(6):457 [article]
  6. Ishihara S.  Tests for Color Blindness.  1972 [book]
  7. http://www.eyemagazine.com/feature/article/ishihara

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