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Efficiency of the Ishihara test for identifying red‐green colour deficiency
Author(s) -
Birch Jennifer
Publication year - 1997
Publication title -
ophthalmic and physiological optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.147
H-Index - 66
eISSN - 1475-1313
pISSN - 0275-5408
DOI - 10.1046/j.1475-1313.1997.97000227.x
Subject(s) - trichromacy , colour vision , color perception test , optometry , color vision defects , luminance , color vision , audiology , optics , ophthalmology , medicine , psychology , artificial intelligence , computer science , physics
Summary The Ishihara test is the most widely used screening test for red‐green colour deficiency. Results obtained by 401 people with red‐green colour deficiency show that the combined sensitivity of the Transformation and Vanishing plates of the 38 plate Edition of the Ishihara plates is 95.5% on eight errors, 97.5% on six errors and 99.0% on three errors. The Hidden digit designs only identified approximately 50% of colour‐deficient subjects. The protan/deutan classification plates were found to be more effective for deutans than for protans. No classification was obtained for 18% of protanopes and 3% of deuteranopes who saw neither figure on classification plates; 40% of protanomalous trichromats and 37.5% of deuteranomalous trichromats saw both classification figures and were classified on the relative luminance (clarity) of these figures. The specificity of the Ishihara test was determined in a previous study (Birch and McKeever, 1993) and the results combined with the present data to obtain the overall efficiency of the Ishihara plates for a representative cross section of colour‐deficient subjects.