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Thread: Are the color blind tests online fake... or am I actually blind?

  1. #31
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    Quote Originally Posted by NorthernDevo View Post
    Interesting topic. I'm one that absolutely relies on my colour vision for my career - I'm a printer. I've taken far more colour-blindness tests than I care to remember;
    I worked in a photo lab for ten years. Colour acuity was a requirement for the job.

  2. #32
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    Quote Originally Posted by Cougar View Post
    Or Mareykan could actually have some color blindness. I certainly had no problem seeing the numbers in the screenshot he linked to, and I'm surprised Mareykan is saying he doesn't see any except for that last one....
    Maybe. Or maybe not. That's the trouble with online tests; they're unreliable.
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  3. #33
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    I shall buck the trend on this one. Online tests in general may have their problems, but this situation is quite straightforward. Those circles have numbers. Most of us here can see them. If you can't, it's pretty clear that there's something wrong in your case. Color blindness is one of the possibilities with which to fill in that "something", and by far the most likely. The alternatives that have been given here just don't add up. Low resolution? The only resolution that matters in a collection of adjacent bubbles is bubble-size, and these bubbles have clearly not shrunk too small to discern as bubbles. Monitor that's amazingly crappy at producing distinct colors right in the area where color blindness most often strikes? Such a glaringly gross defect not only is rare in production to begin with but also is made even rarer in retail, practically non-existent, by basic QC product-testing at the factory, and an exception would have been noticed by its users in other contexts before. The prevalence of color blindness, especially including its milder forms, in the real-world population, is known to be well above any even faintly reasonable estimate of the odds of getting such a defective product (and not having noticed it before). Healthy skepticism of the somewhat unlikely should not drive us toward automatic acceptance of the staggeringly unlikely.

    Quote Originally Posted by grant hutchison View Post
    Actually, colour blind people don't see green as grey, unless they have a very rare, extreme form of colour blindness with monchromatic vision, in which everything is a shade of grey.
    They can, however, be bad at using color words to describe what they see because they can't learn what the words mean. People with normal color vision could call my irises "green" but never "gray", and I've had a color-blind woman tell me they looked "silver" to her, which isn't far off from calling them "gray" (just shinier).

    Quote Originally Posted by DaveC426913 View Post
    For some tests, you might only see a number if you are color-blind.
    How would that work?

  4. #34
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    Quote Originally Posted by Delvo View Post
    .....I've had a color-blind woman tell me they looked "silver" to her, which isn't far off from calling them "gray" (just shinier)....
    Ooh, like Aloysius Pendergast!
    Everyone is entitled to his own opinion, but not his own facts.

  5. #35
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    Quote Originally Posted by Cougar View Post
    Or Mareykan could actually have some color blindness. I certainly had no problem seeing the numbers in the screenshot he linked to, and I'm surprised Mareykan is saying he doesn't see any except for that last one....
    That is entirely possible, but I know a lot about color theory and computers and not a bit about how eyes actually work. I'm sticking to what I know, followed by a suggestion to actually talk to someone knowledgeable in healthcare.

    For the record, I'd make a lousy <insert healthcare professional here> for a lot of reasons. My wife is a nurse and is pretty much convinced I'd be run out of any health facility by a combination of staff, patients, torches and pick-forks.
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  6. #36
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    Quote Originally Posted by Delvo View Post
    How would that work?
    Take a look at plates 18 through 21 here. What's going on is that there's a pattern of lines in reds, greens, and browns that dominates the image. But for people who can't distinguish between red, green, and brown very well, they don't see that distinct pattern, and instead they see a more subtle pattern that crosses those boundaries. If you look very closely, you may be able to see the pattern.
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  7. #37
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    Quote Originally Posted by Delvo View Post
    I shall buck the trend on this one. Online tests in general may have their problems, but this situation is quite straightforward. Those circles have numbers. Most of us here can see them. If you can't, it's pretty clear that there's something wrong in your case.
    Incorrect. The Ishihara test is a printed test; when replicated on a monitor it becomes a very different entity; it has no validity in reference to the original test. Considering for the moment that colour acuity is a spectrum, and one which has no real pass/fail position; calling any result 'wrong' is careless in the extreme. To be clear, most people have some varying levels of colour-acuity; some might be less capable, some might be more. Some - like myself - may have their inherent ability enhanced by decades of experience in discerning fine differences in colour. Colour acuity is not merely natural; it is also a trained skill; let's not forget that.
    Last edited by NorthernDevo; 2017-Mar-11 at 10:20 PM. Reason: Changed 'ignoring' for 'considering'; I changed my argument.
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  8. #38
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    Quote Originally Posted by Delvo View Post
    They can, however, be bad at using color words to describe what they see because they can't learn what the words mean. People with normal color vision could call my irises "green" but never "gray", and I've had a color-blind woman tell me they looked "silver" to her, which isn't far off from calling them "gray" (just shinier).
    That's interesting, and I wonder if it's related to why the prof called evergreens "grey". Red-green colour-blind people have a neutral point in the cyan region of the spectrum - while they certainly can (and do) identify green as being a colour that isn't grey, they can't distinguish shades of cyan from shades of grey. Depending on the species of evergreen the prof was looking at, its foliage could be pretty close to a dark version of his neutral point, making it look dark grey. Although we call these trees evergreen, meaning "always in leaf", they're sometimes not a colour we'd actually call "green" without qualification if we were presented with it on a colour chip. And of course that's a difference that wouldn't be intuitively obvious to a colour-blind person. Likewise, if your eyes are green in the way my mother's eyes are - blue/green/grey according to the light and the point at which individuals draw the line between green and blue - then they may have appeared close to colourless to the colour-blind woman you mention.

    Grant Hutchison

  9. #39
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    What if the evergreen was a "blue spruce" or was illuminated by a blue or cloudy sky but not directly by the sun?

    I don't think I'm color blind, but having worked in color for photography and publishing in HS I thought I had developed a keen eye for shades. When I enlisted, MEPS said I was colorblind because I failed the test. However, I couldn't see the numbers in the images because they flipped them too fast and it was just a blur. But I know that when I look at them I can see an obvious number, but can still see other possible numbers depending on which colors they want me to connect. MEPS then had me do a lantern test, but they didn't tell me what colors were being shown, so my answer was either green or red, but they had white ones which I listed as green because I didn't know it was an option and assumed the lamp was wearing off its paint. My mom thinks I should be colorblind because she claims to be colorblind "in shades", whatever that means and that it's always sex-linked. I disputed that and wonder if maybe I was switched at birth - we do have different blood types too.
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  10. #40
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    Quote Originally Posted by Ara Pacis View Post
    What if the evergreen was a "blue spruce" or was illuminated by a blue or cloudy sky but not directly by the sun?
    Yes, that's what I was talking about.
    It's a feature of dichromatic colour blindess that there's a neutral point within the spectrum that's indistinguishable from grey of the same brightness. For the two varieties of red-green blindness, it sits in the cyan range (for yellow-blue colour blindness it sits in the yellow range). To the long wavelength side of the neutral point, someone with red-green blindness sees shades of a single primary colour we could call ryg, for red-yellow-green; to the short-wavelength side they see blue, but may have an abnormal or absent transition to violet. The neutral point is very narrow, though, and you don't need to move far either side of it to get a sensation of colour.
    So you need quite specific conditions, very close to the neutral point, for a colour-blind person to report "grey" when a colour is present. There's no way that all evergreens would appear grey to someone with the common variety of red-green blindness, but it's certainly possible on a given day, with a given tree, that one might appear grey.

    Grant Hutchison

  11. #41
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    Quote Originally Posted by Delvo View Post
    ...Monitor that's amazingly crappy at producing distinct colors right in the area where color blindness most often strikes? Such a glaringly gross defect not only is rare in production to begin with but also is made even rarer in retail, practically non-existent, by basic QC product-testing at the factory, and an exception would have been noticed by its users in other contexts before.
    I knew a guy who took 3 months to realize his monitor was missing a color, I think it was green. He had normal color vision but this was in the early days of computers with at best CGA graphics. It wasn't till he noticed some text on my monochrome monitor that he couldn't see on his that he realized something was wrong .

  12. #42
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    Quote Originally Posted by Ara Pacis View Post
    I disputed that and wonder if maybe I was switched at birth - we do have different blood types too.
    I wouldn't worry about that because I think your mother was wrong. In neither of those cases do children automatically get the same phenotype as one of their parents. For example, if your father is AO (phenotype A) and your mother is BO (phenotype B) then you can be (by 25% probability for each) A, B, O, and AB. And colorblindness is recessive so even if your mother has it you don't necessarily.
    As above, so below

  13. #43
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    I worked with a programmer that was color blind. The assistant programmer picked all of the colors for the application, but made sure the color pallet was something the a color blind person could distinguish. To be honest, it was rather dull, almost everything was blue or grey. There was one band of very light grey where deep red text would appear, but the contrast was enough that it wasn't a problem.

    I didn't know this until I passed my job on to someone else. The very first thing they did was change the coding reqs to a color coded design where color indicated importance. Guess what happened? Stuff didn't get done in the right order.

    Grrr. There was nothing wrong with "high", "medium" and "low" priority rows, neatly sorted by priority. Worse, the guy had 9 levels of priority plus "when convenient". Do you know when programmers hit "when convenient" items? When you give them a real priority.
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  14. #44
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    They can, however, be bad at using color words to describe what they see because they can't learn what the words mean.
    That's me. I don't know what kind of colour blindness I have. I can see the transition between two 128 value RGB values 1 value apart. I can pass all the common CB tests. But I often misidentify colours, especially lines on screen. And I have huge problems naming non-primary colours. I don't mean just those secret language words women use, but also the difference between eg purple and pink. I know pink when it's Barbie, but when things become a bit more reddish and translucent or fluo I'm at a loss. And it feels to me as if I need a lot of concentration/effort/it feels really tiring to identify some colours or see different colours, even though in RGB I see the smallest difference.

  15. #45
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    I don't think that's unusual, except to the extent that you seem to be worried about it.
    Colour names chop up a continuum into a set of discrete patches, and there are always going to be arguments at the edges, even if we all had exactly the same visual pigments and neural wiring. Simply having (or lacking) words for certain territories of the colour chart influences your colour perception. In Scots Gaelic, there's not much effort to distinguish green from blue - so the Gaels would have been a little puzzled by people who insist on the difference between jade, aqua, teal and turquoise.

    Grant Hutchison

  16. #46
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    Quote Originally Posted by Mareykan View Post
    So neither my father, nor my brother are colorblind so theoretically it should be impossible for me to be so.


    However, when looking at those colorblind tests, I can never see the number.



    http://i.imgur.com/jS2tAn0.jpg


    For example, I can only read the "16" on the bottom right. In the rest of the images all I see are a mass of green with orange fleks, or a mass of Orange with green fleks.


    Not sure if those are fake tests made to mess with people, or if I am actually color blind... help?
    There are any number of issues that might affect an online test, but I would think that the patterns would be visible even with a slightly off color profile, aging display or something...

    If you have a digital camera or a camera on your phone, you could try to display the image you posted on your computer, take a photo of what is displayed on the screen, and post that photo.

    Of course, it is not always easy to get a good photo of a screen, but as long as it isn't over or under exposed, it would probably at least rule out any larger problems with your system settings/monitor.

    Still, it is obviously best to just go to a doctor and have a proper test done.

    From what I understand, the more common forms of color blindness isn't actually a lack of color perception, but rather that there is a difference in formation of one(or more) of the pigments used for color vision from people with normal vision.

    For example, I think the most common red-green color blindness is a "green" pigment that has an anomalous wavelength sensitivity that is closer to the red than in most people.

  17. #47
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    Quote Originally Posted by TrAI View Post
    For example, I think the most common red-green color blindness is a "green" pigment that has an anomalous wavelength sensitivity that is closer to the red than in most people.
    Yes, that's called deuteranomaly - but there are multiple genes for the green pigment, so deuteranomalous individuals have a set of abnormal green cones and a set of normal green cones. They can have anything from a mild defect that only shows up on careful testing, to a severe defect that can only be distinguished from deuteranopia (complete absence of green cones) by careful testing.

    Grant Hutchison

  18. #48
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    Quote Originally Posted by grant hutchison View Post
    Yes, that's called deuteranomaly - but there are multiple genes for the green pigment, so deuteranomalous individuals have a set of abnormal green cones and a set of normal green cones. They can have anything from a mild defect that only shows up on careful testing, to a severe defect that can only be distinguished from deuteranopia (complete absence of green cones) by careful testing.

    Grant Hutchison
    That's what my father had, and it kept him out of the U.S. Naval Academy in the late 1930s. He could distinguish saturated colors OK, but he would have had trouble with signal flags or navigation lights in poor visibility, which would have been critical in sea duty. It was not an issue when the Army drafted him in 1942. Apparently I do not have it, as I can distinguish pastels that he had trouble with.

  19. #49
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    Quote Originally Posted by grant hutchison View Post
    I don't think that's unusual, except to the extent that you seem to be worried about it.
    Colour names chop up a continuum into a set of discrete patches, and there are always going to be arguments at the edges, even if we all had exactly the same visual pigments and neural wiring. Simply having (or lacking) words for certain territories of the colour chart influences your colour perception. In Scots Gaelic, there's not much effort to distinguish green from blue - so the Gaels would have been a little puzzled by people who insist on the difference between jade, aqua, teal and turquoise.

    Grant Hutchison
    True, but in my case it is NOT limited to those exotic colour names. Especially for thin lines, not even primary colours are safe for me. I'm clearly much worse than the rest of my family at identifying colours. At work, I'm the only one amongst hundreds of people who can't see the active yellow line between the white lines on a piece of equipment. If you want to keep something a secret from me, just write with a red marker on white paper.
    Last edited by Nicolas; 2017-Mar-14 at 08:31 PM.

  20. #50
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    Is there an issue in that on-screen tests uses additive mixing to make colours (red, green, blue sub-pixels on the monitor) but printed tests use subtractive mixing (cyan, magenta and yellow inks?)?

    I'd have thought the standard tests couldn't just be translated directly.

    (Sorry if that's already covered, I did read back in the thread and didn't see it.)

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    Quote Originally Posted by pzkpfw View Post
    Is there an issue in that on-screen tests uses additive mixing to make colours (red, green, blue sub-pixels on the monitor) but printed tests use subtractive mixing (cyan, magenta and yellow inks?)?
    There is definitely an issue that online tests simply cannot be controlled. No two monitors even show the same set of colours.
    Heck, I've got two monitors side-by-side on my desk attached to the same CPU, and I still can't get them to look similar.

  22. #52
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    Quote Originally Posted by swampyankee View Post
    I think -- I'm not sure -- that color blindness is a bar to a commercial pilot's license or above.
    Yep. Between that flat feet and every other blasted thing--I couldn't join the Navy. Not even mentioning the skipping heart.

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