4
$\begingroup$

Is there a test method of proving a person being color-blind, without letting the test subject know, that he/she is being tested?

E.g. showing the person cards with colored dots like depicted here is not a valid answer.

$\endgroup$
  • 3
    $\begingroup$ When you say the subject doesn't know they are being tested, do you mean know that color perception is being tested, or they are being tested for something? $\endgroup$ – StrongBad Nov 6 '14 at 9:38
  • $\begingroup$ duplicate of biology.stackexchange.com/q/23733/460 $\endgroup$ – Memming Nov 6 '14 at 15:32
2
$\begingroup$

Depending on the instructions that you give to the person, you might be able to disguise the fact that they are completing a color-blindness test. You could use stimuli like those in the Ishihara test, but instead ask the subject to do a math problem where they add the previous two numbers. You can also tell them that sometimes no number will be presented, and have a few cases of actual blank tiles mixed in with the regular stimuli. If a subject reports the wrong sum consistently for trials that involve a particular hue, you can be reasonably confident that they are colorblind for that hue.

There is also a short test developed by researchers at City University London which has subjects track a square during a movie. It's probably no more subtle than the Ishihara test, but it is less well known and therefore subjects might not infer what the purpose is. See http://www.city.ac.uk/health/research/centre-for-applied-vision-research/a-new-web-based-colour-vision-test.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.