Color Blindness Test by Dr Shinobu Ishihara

Tests 30 Comments

Unfortunately the Ishihara plates are not available at this adress anymore. But I posted them in a new article on Colblindor and you can find them all at: Ishihara’s Test for Colour Deficiency: 38 Plates Edition. Make sure to also visit my Online Color Blindness Tests, to check your color vision abilities.

The Ishihara Color Blindness test – named after a Japanese Professor at the University of Tokyo – is the most well known tool to test for red-green color blindness. Mr Ishihara developed this test almost 100 years ago. It was first published in 1917 and is used since then to check if someone is suffering from protanopia or deuteranopia, the two different kinds of red-green color vision deficiencies.

A collection of 38 plates filled with colored dots build the base of this test. The dots are colored in different shades of a color and a number or a line is hidden inside with different shades of an other color. But enough theory, take the color blindness test by Mr Ishihara yourself and be surprised (or not) of the result.

The above link showes the so called small test. The small test consists of 24 different plates (or cards) and the large test of 38. The plates follow a setup of four different test designs:

  1. Transformation plates – anomalous colour observers give different responses to colour normal observers. [Plates 2-7]
  2. Disappearing digit (Vanishing) plates – only the normal observer is meant to recognize the coloured pattern. [Plates 9-13]
  3. Hidden digit plates – only the anomalous observer should see the pattern. [Plates 14-15]
  4. Qualitative plates – intended to classify protan from deutan and mild from severe anomalous colour perception. [Plates 16-23]
Ishihara Color Blindness Test Plate
Ishihara Plate

It has to be mentioned, that tests like this one are never 100% accuarte. This is due to the two following facts: First of all, every computer monitor has its own color correction. So it never can be guaranteed that the seen colors are really the colors which should be seen. This can falsify the results. And second, easily put there can always be some false positives. This test can therefore not be considered as a medical test for color blindness.

Now let’s have a look at the outcomes. I will show you my results and you can, if you like, compare them with your own ones:

  • CARD 1: 12. Of course, everybody should see that.
  • CARD 2: 3 with a slight shade of an 8.
  • CARD 3: A very confuse 29.
  • CARD 4: Some dot clusters, that’s all.
  • CARD 5: A slight circle at the top.
  • CARD 6: Some dots here, some there.
  • CARD 7: Dots everywhere.
  • CARD 8: Nothing. I mean, I can see the big circle full of little colored circles, but that’s all.
  • CARD 9: Nothing.
  • CARD 10: Nothing.
  • CARD 11: Nothing.
  • CARD 12: Nothing.
  • CARD 13: Nothing.
  • CARD 14: Some lines and clusters but no number.
  • CARD 15: More lines and dot clusters.
  • CARD 16: I would say a 6 on the righthand side.
  • CARD 17: 2, righthand side.
  • CARD 18: A blue (?) line more at the bottom of the circle.
  • CARD 19: Two crosses. One on the left and the other on the right side of the circle.
  • CARD 20: Many colorful dots.
  • CARD 21: More colors and more dots.
  • CARD 22: Some kind of inner circle with three gaps.
  • CARD 23: There is a line, but it has huge gaps in between.
  • CARD 24: I can see that one…

If I try to make a conclusion out of my views I would say I am suffering something between strong protanomalia, protanopia and complete color blindness. Yes, I knew it before and I know it even better now: I am colorblind. But at least I could spot the first and the last plate easily.

Further readings:
Ishihara Color Blindness Test at Wikipedia
The Ishihara Color Vision Test
Ishihara Test for Color Blindness

Direct link to The Color Blindness Test by Mr Ishihara.

30 responses on “Color Blindness Test by Dr Shinobu Ishihara”

  3. Paper

    Thanks.. I found your site to be very useful and approachable. I added a hyperlink to your site in my post about colour blindness, I hope you don’t mind.

  7. Marko

    I can only see 12 in first plate.
    Found out i was color blind at age 15 while taking an obligatory test for army.
    My color vision is so poor that doctor I did colorblind test with wrote his doctorate on my case.
    So dont panic, I always say to myself that others simple dont see colors the way I see them :))

  10. Mik

    Thanks for the plain-talk explanations. I think these tests are designed for cards printed in a specific way and distorted results will occur when viewing on a monitor, so no conclusions should be drawn. If that is correct, more reminders to that effect are needed.

  11. Gene

    Linking Ishihara test results with color blindness has been a huge misconception for decades, and now it is greatly enhanced by the Web. If you search for “vision test” and such, all you get is Ishihara or related tests, unless you know where to look.

    If instead you asked an optometrist, he would tell you that Ishihara’s is a very crude screening test that has zero diagnostic value. It is a cheap way of selecting people who *are not* color-blind. But it cannot make a positive assertion about those failing the test.

    If you can’t pass an Ishihara test, you need a more careful evaluation (that is, if you are concerned about your vision at all). Ask your doctor, or check this out:

    http://www.biyee.net/v/color_vision_test/

    I fail almost all Ishihara tests, but I have done more than a 1000 of the above tests, just for sports, and haven’t failed a single one. There is no way I can be color-blind if I distinguish the smallest variations of color that my computer screen can produce.

    Have fun. Just make sure your monitor is not completely out of whack.

    http://www.lagom.nl/lcd-test/

  12. Surya

    can any one please give the link of the web format of 38 plate ishihara book….or the actual images in a sequential format

  13. Dave

    I can get about 2 or 3 cards right when I test. But I can point colors out to you all day and night from a reasonable distance. Sorry but that test has always thrown me and I’m not a doctor but I don’t think it makes an accurate determination of whether or not you are color blind.

  15. um

    Reading the comments here of those who try to justify their failed test is kind of amusing:

    “It is a cheap way of selecting people who *are not* color-blind. But it cannot make a positive assertion about those failing the test”

    Are you serious? So you can’t read the numbers even though 90% of the population can and you’re saying that it doesn’t make a positive assertion about those who fail the test? I guess the only other conclusion a person can come up with is that you don’t know how to read numerical digits yet.

  16. Gene

    Yes, I am serious, and your conclusion regarding the perception of numerical digits, silly as it may sound, is a good metaphor for why the Ishihara test is faulty. I do not (yet) know how to read numerical digits through noise, and will readily admit that my ability to do so may be inferior to that of the majority of the population.

    The problem with the Ishihara test is that stresses one’s senses in ways that have little to do with color. In fact, I can now tell you that some of the plates become more readable to me after I remove color from them, which amounts to noise reduction, in information-theory-speak. This test is simply too noisy for making any assertions, positive or negative. Granted, it catches more than it loses, but that only makes it good for war-time recruiters. There is no practical use for it in normal life.

    I am not trying to justify a failure at a test that means nothing to me; I just want to give a heads-up to those people with normal color vision who might be discouraged from pursuing color-sensitive occupations after failing a faulty test, which has unfortunately become a medical standard. Those please take a read:

    http://www.faa.gov/about/office_org/headquarters_offices/avs/offices/aam/ame/guide/app_process/exam_tech/item52/amd/

    Aviation is one of the most color-critical industries, and they will let you fail half the Ishihara plates normally, and even if you fail more, you will be eligible for specialized tests. Clearly they don’t hold it in high regard.

  20. geryl estaniel

    how to prevent color blindness?
    and what is the sulotions?
    do we have a medicine for that?
    thak you i hope you response

  21. jon

    hey so i’m tryin to go into the navy SEALs and i passed everything cept my color teest, i took a secondary one after that tho with the red, gree, and white light and aced it. I gotta figure sumthin out to get around this, it’s just little shades not really bad, but to get into SEALs i gotta pass that test. need some help… any suggestions?

  22. Suzette

    Hi! My 6 years old son is confirmed colorblind too. He has mild red-green defect. Do you think he would be able to appreciate 3D movies like the Avatar, which uses 3D glasses that is based on red-green lens? Like you said, he can differentiate red and green though. However, he often have difficulties differentiating green from yellow or orange. Not the same way described by many other who have colorblind.

  23. Gene

    Suzette,

    You can test that very easily. Get a cheap pair of paper-framed
    glasses (they usually cost a couple units of currency, wherever you
    are) and ask your son to look at them and tell you whether he
    perceives the colors of the two lenses as distinct — which will only
    be important for viewing color anaglyphs — and more importantly,
    whether they seem to be of comparable brightness. If one of them looks
    much darker than the other (to the point he can hardly see anything
    through it), then it will not work.

    Even an image such as this can be a good test:

    http://www.underground3dmovies.com/anaglyph%20glasses.JPG

    The typical lcd dyes in your computer screen will have similar
    spectral windows to those in the anaglyph glasses, so if he sees them
    as differently and neither is too dark, go ahead and buy the glasses.
    You will find plenty of anaglyph images on the web to test against,
    once you’ve got the glasses.

  26. Rick Sunbury

    I was denied a job doing security forces in Afghanistan, because the DoS say’s being color blind is a disqualifier, I was a Federal Law Enforcemnet officer at the Chicago Federal Reserve and a Marine (infantry and security forces)i can see colors just not the ones on the test. It never affected my duties and i’m curious to know why it’s a disqualifier. I can actually pick up and detect movement very well and see persons in camoflague, hiding, with no problem.

  27. Gene

    Rick, if you want that job, locate the superior authority and appeal. Rejecting a job candidate for failing an Ishihara is stone-age madness. It could be justified at the time of war, when rough-and-ready decisions needed to be made, but not now, when accurate diagnostic methods are available.

    The algorithm goes as follows (normally):

    Step 1: You pass Ishihara test -> job done
    Step 2: You fail Ishihara -> you must be tested

    Now, you will perhaps be amused to know (but don’t make any conclusions until you are properly tested) that truly colour-blind persons are rather more sensitive to patterns than the normal ones. Camouflage is a classical example. During WW2, colour-blind field observers scored so well that the recruiters were given special orders to look for the colour blind civilians to fill just that role.

    http://www.time.com/time/magazine/article/0,9171,772387,00.html

  29. Suzette

    Just an update on my son’s experience in the 3D (he is colorblind). I brought him to the cinema and he could see the 3D effect. We have tested a few times and he could tell the difference, so yes colorblind can enjoy 3D movies.