Thank you for that, the number of times I have been asked to "describe what I see" for the benefit of someone with normal colour perception. As most of you know, this is not possible, akin to describing blue to a blind person. Now, at last, I can just direct them to this site and let them see for themselves.

When I first chose Color blindness for my biology project, I knew it would be really interesting. But when I clicked on this website to answer a question of mine, I saw the pictures. It makes me relize how amazing it is that I can see the colors that God created. Then there are others that have to see all the poopy colors ever day they wake up, knowing that they aren't going to see something amazing in it own color. Which is super sad to think about. Thank you for letting me see how it effects people.

I HAD A PAIR OF RED LENS CLIP ON SUN GLASSES TYPE, THAT I COULD PUT ON AND PASS THE COLOR BLIND TEST AT MY EMPLOYNENT WHERE IT WAS CRITICAL TO MY JOB. I HAVE SENSE MOVED AND LOST THEM AND LOOKING FOR A MANUFACTURE THAT CAN MAKE ME ANOTHER PAIR. THE SHADE IS BRIGHT RED, AND WITH THEM,I COULD PASS THE COLOR TESTS THAT WAS REQUIRED. DO YOU KNOW OF ANYONE THAT MAKES THESE RED CLIP ON GLASSES ANYMORE. i NEED ANOTHER PAIR MADE. L. BOSSONG 256-216-6992

I don't think that you should hate being color blind. There is not inherent characteristic of color. It is all perception. Primates are the only eutherian mammal to evolve trichromatic color vision. All other mammals are essentially color blind. There are three genes that code for opsin in humans and old world primates. Opsin is the photopigment in cones that differentially responds to spectral energy. The short-wavelength (s) cone is code for on our body chromosomes and pretty much all mammals have this opsin and it is fairly invariant. There are two genes on the x-chromosome middle (m) and long-wavelength (l). There is much more variation in color vision in humans than in old world monkeys (8-11% in caucasian males). There are two ways of being color blind. A person could have two functioning cones (M and L) on the x-chromosome but mutations have occurred that cause their spectral sensitivity peaks to shift so that they are closer together. Therefore, light that differs spectrally sends the same signal to the brain and is "perceived" as the same color. The distance between the two peaks can explain the variation in color perception for some of the people commenting. Another way is to have a mutation in one of the cones that makes the cone non-functional or have the exact same cone at both genes due to meiotic crossing over on the x-chromosome. Males only have one X so if there is a mistake in one gene there is not another x to rescue. THere is also a large amount of variation in female L cones. Therefore, a female with two different L opsin genes on each x-chromosome could possibly have a better ability telling different shades of red and pink apart. So should a color normal female HATE being normal instead of being a super red seeing female because their world must be different or "more beautiful"? It is only perception. Color normals have no idea how you see the world. BTW, one of the possible hypothesis as to why so much variation is maintained for a long period could be because there are times when dichromats (color blind individuals) do better than color normals.

http://www.opticien-lentilles.com/daltonien_beta/new_test_daltonien.php

I'm a color blind too like all of you. The doctor told me that I had a R/G color blind. I couldn't see a green color when I saw test. I could see the number from first page until I met The paper contain green effect. Oh my God, I was shock that time . I felt like a stupid person. I had no trouble with travel light well. I can see the red light just like red apple or red eye monsters. But I'm not realize that the green light is much like white pale. My dream of becoming Communication Visual design Student has broke up. Because the faculty need requirements of Not color Blind. My skill of drawing and painting is useless. I don't how to do because I love them. At the end, My mom told me that color blinds isnt mean that I'm useless. Do you know? My mom advise is right. I have skill other which not allowed to see a color. What about Business Management? I can become the richest man someday. World without colors is more beatiful than Colouful world with the war happen. Smile Blooming (^_^)

i remember growing up i could see the numbers in the dots but now i cant being 25. i have spent many hours tonite researching this color blindness many call it. i can see colors just fine, red ink, light blue shirt, green marker. i even took the Farnsworth test online. I aced it with normal vision. But when it comes to the numbers in the dots i cant see some of them. Does anyone know what i have? My vision is normal , colors are just fine, just cant see some of those numbers. And for the "congress and pass a bill to take away my drivers license" Effay the have come close. try to get your CDL's being colorblind. they think because you cant see some of the numbers the great professor designed. u wont be able to drive.

I suppose I fall in the group of people that are technically colorblind and while I can't see the number in the first image, I can see the differences in every other image clearly. While driving I can clearly tell the difference betwee the red and green lights based on more than their position. The government acknowledges that the plate tests can't always accurately judge the level of colorblindness. Apparently I'm barely R/G colorblind because I can easily pass a test that involves shining red, white, and green light at me, allowing me to serve my country. Additionally I've heard that R/G colorblindess has some benefits in low light environments or environments with alot of blue light. Anyone else heard anything like that?

First off I cant see the 45 but then its about 50/50 for the other pictures. I can see the dress differances easy and the stop light but most of the others are pretty much the same to me. Something interesting that I feel they cant know how to get right in these pictures is whether we see it as red or green. Going by what other people have said for the dresses pictures, to normal vision people the one on the left is red and the one on the right is green. The one on the right is suposed to simulate color blindness, but if we are RG color blind then some green will show up as red instead of vise-versa. I really dont think a normal color person can ever correctly make a picture for showing what color blind people see. They just cant grasp it since they cant see it and theres so many levels to color blindness.

Interesting article and interesting comments.

I am definitely color blind in some way, but I'm not exactly sure what type I have. I can distinguish all the colors when they are in their pure form, but similar shades tend to look one way or another for me. I guess you could call it color deficiency?

As for the pictures above, I can see the differences in all of them, although there are certain anomalies. Here are some notes:

1. I can see a difference in color in dots between the two Ishihara tests, but the dots with the "extra" color in the left drawing don't stand out enough from the other ones to form anything distinct. If I tilt my LCD monitor back, I can clearly see the "45". When I tilt it forward again, I can note the difference in color better, but, again, it's not a vivid enough distinction for the "45" to register.

2. With the berries on the branch, the berries in the foreground look vastly different to me, but I needed to read someone else's description in order to even realize there were berries in the background.

3. The two versions of the girl's dress are as different as night and day to me.

4. The Christmas tree is the most complex one for me: at first I didn't notice a difference, but then it seemed that the globe ornaments in the left picture were definitely more red than the ones on the right. The ones on the right definitely do not contrast as much with the tree, but it would be difficult for me to say what color they are. The color seems a vague, darkish reddish
greenish brown that doesn't register really as anything to me. I think in this situation, I would say it is whatever color anyone told me it was and have no problem if they suddenly changed their mind.

5. It is clear to me that the man's face on the right is reddish color and greenish on the right, but it took me a couple of seconds to realize this the first time. On subsequent viewings the distinction was automatic.

6. The photos of the flowers, berries and the ice cream cone seem significantly different enough to me to notice. With the flowers, though, I would be hard pressed to name what color they are, but I think that has to do more with my education/knowledge in color than with color blindness. Although the flowers on the right are another example of what is a vague color to me.

7. The map was just like the face, although it took me a little longer to notice the difference. And just like the face, once I noticed the difference, the distinction was automatic on later viewings.

8. The Chinese picture I can just barely notice a difference, particular with the flowers floating to the right of the man: the ones on the left are much more red than the ones on the left (like the globes on the tree). I can't see much of a difference between anything else, though. Of course I can "see" the lack of red in the right hand picture, but it just isn't a big deal; it doesn't change the picture very much for me. It's distinctly different only upon examination.

9. The two traffic light pictures are completely different to me.

The conclusion this break-down brings me to seems strange to me: red and green are vastly different colors to me, but not as different as they are to people with normal vision. How can qualities that seem like polar opposites to me admit of being more or less different?

What is also interesting is how my different vision effects me cognitively, particularly with blue and purple. I can see the difference between blue and purple, but since I don't see the red in purple as vividly as people with normal vision, purple and blue seem like two different versions of blue to me, although distinct, simply because the more bluish purples look blue to me unless I look at it closely and find the red in it. It drives my normal color vision girlfriend (who, by the way, is myopic and has dramatically worse night vision than I have) crazy when she corrects me as having called something purple something blue, and I say "Oh yeah, I guess it *is* purple, upon closer inspection." Her response is: "Well why didn't you call it purple in the first place, if you can see the difference?" My response is: "Purple is a kind of blue." Although my senses can distinguish colors, because the differences between them are more muddy, my categorization of them is different from other peoples', in addition to my sense-experience.

This makes me wonder: is it possible that, perhaps, this different perception of colors has to do with a cognitive bias? That maybe the way I identify and objectify colors actually influences the way I see them? What I mean is, could it be that the reason I see colors differently is because I think about them differently? I know the issue is not so black and white (or red and green, har har har), but maybe both factors influence "colorblindness." Could it be possible that I really do see things the same as other people, ocularly speaking, but I can't tell the difference between colors at similar shades because I have a mental bias for distinguishing "shade" before distinguishing color? Maybe it's that I perceive brightness and shadow more *intensely* than others (either by choice or biologically), and therefore see color as more accidental, less as a substantial, unchanging quality of objects, and so less intensely. Do you see what I mean? Above I noted a couple places where I could clearly see colors, but the color was "vague." This seems to have a lot to do with cognition, at least in addition to if not in exclusion of sense perception.

Maybe the reason why our perception of color seems more fixed than our perception of other things is because it's a basic quality of the world around us, and we're taught to make distinctions at a much younger age than we are with other things. Perhaps if color was not a part of our education, part of our culture so much, more people would be "color blind." Take race as an example. You learn to distinguish facial features of people in your immediate vicinity before learning to distinguish people that have vastly different characteristics. There is a common complaint that white people cannot distinguish between black or Asian people very well, and I think it's true. The differences are not emphasized in people's minds because they are not called upon to make distinctions. I am a white guy who has studied Asian cultures and languages my whole life, even lived in Asia. I can tell the difference between a Chinese person and a Japanese person on sight. I'm probably in a very small percentile of white Americans who can do that, but the difference seems obvious to me. Of course there are gradations (race is, ultimately, something completely variable and perhaps non-existent from a scientific standpoint). But most white Americans could not distinguish a very Chinese-looking person from a very Japanese-looking person in any way whatsoever.

I chose this somewhat controversial example among others because I find it a good example when trying to explain my experience of colors to other people. When they ask "What is it like being able to notice the difference between blue and purple but only after a close examination?" I can respond by saying "What is it like not being able to distinguish a Chinese person and a Japanese person?" Or Mandarin Chinese and Cantonese. Or Chinese writing with Japanese writing. Or Mozart's music and Haydn's music. After giving so many of these examples, it dawned on me: maybe my difficulty in distinguishing purple and blue is because my grasp of color as a whole is just not as fine as others', and rather than being like the difference between a disabled person and a healthy person, it's more like the difference between a newb and a connoisseur, someone with no experience or insight and someone who does. It's just that some bias in the way I perceive light prevents my mind from pressing forward to make the distinctions.

Of course you are going to say, recognizing facial features is just a matter of training, but there is biological evidence distinguishing colorblind people from those with normal color-vision. This is true, but I am wondering if in those cases where the biological difference isn't great, what might have been no difference at all grew to be one because of thought patterns. That is, what if there are people who are biologically colorblind that pass vision tests because, by chance, their upbringing emphasized color distinctions more than in others', and what if there are people with normal vision who think they are colorblind because they are simply thinking about colors differently?

Thank you for bearing with this very, very, very long post. I hope this made sense to people. I don't have the answers, I just find these to be interesting questions, and this is how I want to be talking about colorblindness. This is something I find very fascinating, and I'm glad people are talking about this subject in this way. Like many others, I'm sick and tired of that stupid "What color is this?" game! I know what color it is, you idiot. I just don't identify colors the same way you do.

P.S. As I preview my comment, it does not seem to be recognizing my paragraphs. I apologize if this carries over to the final post and the whole thing is one big blob. Oh well.

I've always wondered about this. I've been blessed with not being colorblind (at least, I think of it as blessed), but I have a feeling that, had I been born colorblind, my main problem would be with PEOPLE telling me I was disabled, not feeling disabled myself. I remember a talk with a guy in my class that was slightly colorblind about a dark blue notebook I had. He kept calling it purple. Eventually, he did mention that he had problems distinguishing some colors, and I've wondered ever since how colorblind people saw it. Thanks for posting this article. BTW, about the natural selection thing...telling ripe fruit from unripe fruit probably works much better if you use smell and feel than color anyway, and seeing a tiger in the grass would probably be easier for colorblind people. Despite the normal notion of grass as green, in areas where lions live, like Africa, the grass is probably much drier and more of a straw yellow-brown color. That's why lions have been able to get to the top of the food chain and haven't been killed off by natural selection due to starvation yet, they blend in. Colorblind people rely more on other faculties than color, so I'd imagine they'd be much better off around lions in Africa than the rest of us so-called "normal" people.

I'd have to agree with the post below about LEDs. I hate them with every fiber of my being, since the three most common colors are also the stoplight colors. Imagine having to look at a battery-charge indicator, needing a full battery (which is green, apparently) and not a charging battery (red, so they tell me). Perhaps trying to use a swipe card (such as the ones you see in hospitals and banks). Green means open, amber means enter code or swipe, and red means security is coming. Here you are, just trying to get to work, and now are wondering who all these idiots are that are now surrounding you. (BTW, no I couldn't tell a single difference between any of the pairs, with the exception of woman in the dress... on the right, the dress is brighter, but otherwise appears to be the same color. Also, what is the difference in the pictures of the grinning dude with the button-up shirt and the lanyard around his neck? Second set, first pair.)

It is curious that such a high proportion of males have colour blindness. One would have thought that it was a characteristic that would be eliminated by natural selection (can't tell ripe fruit from unripe - can't see the tiger in the grass etc.) So, perhaps there are advantages, as well as disadvantages. I have been told that in war time, colour blind people make good spotters, not being easily deceived by camouflage - I suppose because we are more used to looking for shades and textures. I have also been told that the eyes adjust more quickly to low light levels. Does anyone know of any studies done to compare advantages and disadvantages?

I can see it now. Ten years from now someone who read this post is going to be elected to congress and pass a bill to take away my drivers license (possibly under the guise of defeating global warming). Thanks in advance for relegating me to a bicycle!!!

I am 14 yrs. old, and im pretty much ok with being red green colorblind and slightly blue yellow. What I would really love to see is a picture altered for colorblind people to see how a normal person would see, because its always the opposite. For once I would just like to see what a rainbow actually looks like. oh and it doesnt help by you people always saying how sorry you are for me, and how much you wish you didnt have my vision

I hate being colorblind. It is definitely a disability. I mean as humans we can view only a narrow section of the EM spectrum--specifically the visible spectrum! Now here I am hindered from a true perspective of the visible spectrum, something all ready limited in itself. Someone figure it out, slice my eye open and toy with those cones/rods, I just want to see the difference!

I am red-green color blind, like many of you. Clearly there are levels of the condition, though, as I could not for my life see any numbers in the first photo, but was very aware of the difference between the red and puke colored dresses. Also interesting is the phenomenon described where color blind people saw both stop lights identically, as in, mentally supplementing in color that is not present. Describing this ability/handicap is especially difficult, and I often find that if someone is to say, for example, a specific block is red, I will see it as red, but if they say it is green, I see it as green. It is a sensation similar to looking at an optical illusion and switching between equally dominant visual perceptions, does anyone else experience this? PeterLC also touched on distance and the amount of time spent studying a subject, both factors in color recognition for me. ____________________________________________________________________________________ A side note on beauty, colorblindness, and tact: It is impossible to say whose world is more "beautiful," a colorblind man's or a person with normal color perception. In the same way a blind man will find beauty in textures, sounds, and smells in a way impossible to me, a color blind man may have his own sense of beauty beyond the perceptions of a normy, and vise-versa.

Did you know that color blindness was a survival trait from our nocturnal tree dwelling ancestors. The advantage is meant to be a high contrast night vision. Not much call for seeing colors at night.

For annonumuss: because of color blindness there is a standard for traffic lights... red at the top, followed by yellow and green at the bottom. This way they can drive too.

I have RG colour blindness and looked at your site with my wife who isn't. It was a surreal experience. I could see no difference between the left and right pictures, whereas she said that she could see huge differences. So far, what I expected, but then we talked about some of them. We started with the traffic lights: I can see a reg, yellow, green traffic light in both pictures, she said that the ones on the right were all shades of yellow !! So who's seeing the truth? I couldn't see the number in the very first picture on the one on the left at all, which didn't surprise me. She could though... In some of the other pictures it was strange to hear my wife say what she thought the colours were on the right. When I described them she said that's what she saw on the left, but then I said that the two were the same ! Good fun, and very thought-provoking. Well done...

This information was fascinating to me since I'm the mother of 2 sons who are color blind. The oldest is the RG color blind and he's an electrical engineer. I had no idea what things looked like in his eyes and this is amazing. The second son has more of a shade blind problem. I discovered this when he was quite young and asked me why I was making GREEN NOODLES!! His problem is with greens and browns. The noodles were in a tan gravy but they didn't look that way to him. Thanks for this information.

In the Last picture, it shows how color blind people are not able to see if the traffic light is on red or green,they're only able too see if it's yellow, which is not good. Does that mean they're not allowed to drive? or Are there options for them? If so, What kind of options? Thank you for your time.

This is really cool i never realised that before and the guy who said that that the simulated colour blind pictures are better and have more harmony. You are a fool. Them other colours add so much more depth to the world and so many great pieces of art would be nothing anymore and so much more other things imagine what the world would be like if we could see more colours then are in our possible spectrum of viewing it would look even more amazing and wonderful.

A friend, in his late 50s, told me that, as a keen 18 year old, he started to study to be an electrician in the UK in the mid-1960s. It was only *after* his final exam, 3 years later, that he was tested for colourblindness - he was red-green colour blind and banned from being an electrician...

I have superman's eyes. I can clearly see the differences between all of the pictures above. And yes, I can read the "45" in the dot diagram. On top of that, I have perfect vision and both eyes intact. It makes me wonder why they call it "color-blindness". Why do you need a modifier there? Why not simply call it "blindness" since "color-blind" people are blind to the obvious fact that each of those pictures were different.

Also, and this is for all you "blind" people out there, the girl is way hotter wearing red than nasty yellow-mustard.

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OMG, I'm glad I am not RG blind. That red dress seems to be a crappy green on the right. I hate that color, but the red is very nice.

i'm not colorblind, but i just want to say the pictures on the right were more beautiful than the pictures on the left. there seems to be a gorgeous harmony of colors in the world of a colorblind person.

I've read so many of the comments on this site, and knowing people who are red/green colorblind, like myself and friends, I've come to understand that there are many different strengths of impairment. Looking at this page though, I could tell absolutely no difference in any of the pictures, except for the christmas tree. The christmas tree picture just seemed to look darker and more shadowed, but really I could tell no color differences. Anyway, this was a great page, thanks for creating it and I've e-mailed it to many of my non color deficient friends to help them understand.

i can see the 45 in both pictures. is that wrong?

I hear a lot of colorblind people saying that they can see obvious differences in these pictures. Lucky you. I'm red/green colorblind and I can hardly tell any difference at all. Only in a couple of pictures are there small differences between them, but by and large its all the same to me. Oh and btw, I don't know if you've ever had this argument with relatives, but peanut butter is in no way, shape or form brown. Its some kind of darkish tanish color, but I would never call it brown. I find this discussion seems to come up every now and then and I always walk away frustrated. Do you colorblind people back me up on this one?

"Also RG Colour Blind's" remark about red flowers "springing to life" under filament light or moonlight got me thinking. What's missing under those conditions is an excess of BLUE light. I wonder whether wearing yellow glasses, thereby cutting down the blue component of sunlight and fluorescent lighting, would improve the RG-colorblind person's ability to distinguish red from green. (Such glasses are -- or used to be -- commonly available for e.g. pilots, for the purpose of sharpening vision. They actually do sharpen vision because they cut out blue light, which the eye doesn't focus as well as red and green.) Maybe I'm wrong, but I'd love to see one of you try this and report back. I also wonder to what extent R/G color blindness is affected by viewing images on computer screens, photographs, and printed media (such as magazines) rather than by direct viewing in the "real world." In the real world, objects reflect a wide variety of different wavelengths -- but computer screen phosphors/LEDs, photographic dyes (in film and paper), and printing inks reflect only a relatively limited selection of wavelengths. Whatever color you "see" on the computer screen, for example, you're really seeing only a specific mixture of the same three colors at all times. So I wonder whether computer/print based tests are really testing only the ability to distinguish THOSE PARTICULAR colors, rather than the full range of colors found in nature. On the other hand, the eye's cones are sensitive to specific bands as well, so maybe the two effects cancel out. Lastly, I'm interested in this "Munsell test;" where can I take it? I'm one of those who can look at a color here, today, and pick out an exact match next week, somewhere else, but I'd like to see an actual percentile score now that I've heard it's available. :-)

Chung Dha Lam, I disagree. All of the images look precisely identical to me. In my opinion, these are spot-on.

I am also unable to see any difference in most of the photographs. My 8-year-old son had to describe the differences to me. He could see the number in the first pic and all the variations in great detail. I'd say it's a pretty good representation of my particular case of colorblindness.

The Gimp filters are great, but wouldn't it be great to make a filter for the whole screen (task tray / hot key trigger) that would transform the whole screen into color blind mode for a while? Not matter what applications you have open (say, a program or website you are developing) - it would be easy to check if it has show stopper color blind problem areas.