August/September 2016 (vol. 13/2)

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Research Plus

Colour vision testing

Colour vision (CV) tests are mandatory in several transport industries, but there is inconsistency in both their use and their ‘colour safe’ pass/fail rates, according to this systematic review. The pass/fail rates depend on the type of test, the conditions under which they are taken and the assessment criteria. The 20 included papers were mostly of good methodological quality. Many regulatory bodies still use Ishihara plates in combination with secondary lantern tests, but these cannot accurately quantify type or severity of CV deficiency. Modern computer-screen tests, such as the Colour Assessment and Diagnosis, and the Cone Contrast Test, have higher specificity and sensitivity, and are able to quantify the nature and level of CV deficiency. The authors conclude that industry standards should meet job-specific CV requirements, with tests validated so that they do not unfairly discriminate against those with CV deficiency but who can safely do the job.


  1. Occupational Medicine 2016; 66: 268–275. doi: 10.1093/occmed/kqw012.


Occupational Health at Work August/September 2016 (vol. 13/2) pp40