Talk:Color blindness

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Archive 1 Archive 2

Statistics

Are there any statistics that show the percentage of people with multiple trichromacies? For example, I have Protanomaly and Deuteranomaly and am curious as to how common that is. Are the various color blindnesses randomly overlapping, or are persons with one type of color blindness more likely to have others also? 24.237.218.205 (talk) 05:21, 8 December 2007 (UTC)

Cure!

Scientists have recently been testing a virus that has cured color blindness in mice. It's very new, but I think that something should be written about it in the article. (I'm color blind, so at least for me, this is very exciting). --Ssov 03:00, 29 May 2007 (UTC)Ssov

Ah.. were did you read about this? Color blindness may be a result of many different causes. But I have a hard time imagining how genetic color blindness may be cured. Can you cite references? Fred Hsu 02:37, 30 May 2007 (UTC)

There's a recent AP article he may be talking about. Looks like it's a retrovirus that may be used to treat achromatopsia. --Xanzzibar 04:43, 30 May 2007 (UTC)

Yes, I have heard of a cure too! I also hear it works!!!--Mary divalerio 16:57, 7 September 2007 (UTC)

British or American spelling

The following is the last post of Archives 2 :"I just changed most of the "color" to the correct spelling of "colour". i dont know what kind of ignoramus would think it is spelled "color" because that is what the americans think and we all know how thick they are, don't we?—The preceding unsigned comment was added by David Cat (talk • contribs) 19:44, 15 October 2006 (UTC)."

Since this was archived and not commented on, I'm bringing it back for discussion. As per the section on varieties of English in the Manual of Style, articles should 1) use the same dialogue throughout, and 2) follow the dialect of the first contributor (if there is no strong tie to one nation and other words cannot be used). As color/colour blindness doesn't have a strong tie to any one specific nation and has the word color/colour in it, the spelling should follow the dialect of the first major contributor, which was American English.

This has obviously been a problem - looking through the edit history I saw that the spelling has been changed to British English at least 3 different times, and then changed back. Since there have been no non-vandalism edits since the last change to British English, I'm reverting it. Natalie 22:23, 27 November 2006 (UTC).

Gee, a classic edit war. Let's see here... ah, here we go. For colour blindness see this page. --205.201.141.146 20:24, 27 June 2007 (UTC)

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Other color deficiencies?

The article as is only addresses the classic definitions of color deficiencies. There's nothing wrong with that, but should it also include other color deficiencies or should they be in a separate or alternate article? Specifically, I'm thinking of the common age-related color deficiency do to the yellowing of the lens, and also the forms of low-light color deficiency (which I'm not very familiar with). --Ronz 20:46, 29 November 2006 (UTC)

I'm trying to research the colorblindness that I suffer from, but I can't seem to find it. To my knowledge, I can see every color, but similar colors are very difficult for me to distinguish when next to one another, and certain colors, when I view them on their own (brown, red, green, grey and some shades of blue, for example), I can't tell what color it is at all. Does anyone know what kind of colorblindness this is? --Steam Giant 12:53, 16 March 2007 (UTC)

Heredity

The article says, in regards to being a

Genetic red-green color blindness affects men much more often than women, because the genes for the red and green color receptors are located on the X chromosome, of which men have only one and women have two. Such a trait is called sex-linked. .... In turn, a carrier woman passes on a mutated X chromosome region to only half her male offspring.

This is going to sound like hair-splitting but is this sort of... inaccurate? It is possible for a carrier woman to have no colour-blind male offspring or even 100% of male offspring colour-blind. It's just that statistically she will have a 50% probability of having a colour-blind son, because it's the chance of which X chromosome will be present in the zygote at conception. That means if she only has one son, it's 50-50 if he's colourblind, so the result would be either 0% or 100% colour blindness in male offspring... you get my point. I'm pretty sure this is right, but I could be wrong. If not, could someone change it so maybe kids learning about heredity don't get confused? - spider84 (password problems, can't log in) 220.237.244.200 09:10, 3 December 2006 (UTC)

You are exactly correct, and you're not hairsplitting (in my opinion, anyway). I updated the text to: "In turn, a carrier woman has a fifty percent chance of passing on a mutated X chromosome region to each of her male offspring." – Zawersh 21:13, 18 April 2007 (UTC)

Regarding the Sample Images

For reference, following are the removed images that are referenced in this discussion. -- – Zawersh 13:04, 25 April 2007 (UTC)

• This is a sample image. The pictures below should look similar to people with normal vision (containing numbers, in this case 83), but some of them will not be visible to people with a color vision deficiency. The contrast in these tests is much subtler than commonly seen in other similar tests.
  This is a sample image. The pictures below should look similar to people with normal vision (containing numbers, in this case 83), but some of them will not be visible to people with a color vision deficiency. The contrast in these tests is much subtler than commonly seen in other similar tests.
• This image contains the number 37, although someone who is protanopic might not be able to see it.
  This image contains the number 37, although someone who is protanopic might not be able to see it.
• Someone who is tritanopic might not see this number (56).
  Someone who is tritanopic might not see this number (56).

Those images tend to be more visible on a monitor set to a lower level of brightness than on one set to a higher level of brightness. I find this quite misleading. —The preceding unsigned comment was added by 24.84.41.35 (talk) 04:40, 11 December 2006 (UTC).

They're useless on an LCD, so I've removed them from the article. boffy_b 08:22, 17 January 2007 (UTC)

Should we remove images that are fine for readers with better quality monitors? They still give all readers an idea of what the tests are like no matter the monitor quality. --Ronz 17:10, 17 January 2007 (UTC)

Actually, they are only useless when the LCD isn't used in its native resolution, but it can be told to the users. I think they could be kept. Thomas Bertels 16:08, 18 January 2007 (UTC)

I'm slightly colour-blind (and it IS COLOUR, as my goddamn english teacher keeps telling me), and i think these images are only accurate for people wha suffer from strong-colour blindness. and how do people get these images, as you cannot see out of another person's eyes? i do not see how you would tell that green looks very blue to some people. -Grim- 00:27, 16 March 2007 (UTC)

It may be worth noting that these images and many others were discussed (now in the archives) before they were used (and at times removed). See Removed images, Color blindness test, Cone fundamentals and generating a spectrum, Either my monitor is pretty bad or the images aren't really great., What I see, Spectrum picture. Also see below, Rainbow Errors?. Every time a set of sample images get put up, they get pulled down several months later because someone doesn't like them.

We seem to be trying to fill three illustration needs with the various images proposed and used for this article over time: show what a colorblindness test looks like, simulate colorblindness for a non-colorblind person, and actually test for colorblindness. The last criterion is impossible to achieve. This is not a testing facility, and with monitor variations and individual colorblindness variations, we will never have an image test that works properly. So let's discard that one.

To show what a colorblindness test looks like, we should use an actual real world colorblind test, preferably one that's widely used. This makes the images in Ishihara color test good candidates. I don't think we should not make up our own colorblindness tests because those aren't illustrative of real colorblindness tests. And I also don't think it matters if the image we use actually tests colorblindness when displayed on a monitor -- it's there to show what the test looks like, not to actually test anything. I'm going to re-add an Ishihara image to the article for now.

To illustrate colorblindness by way of simulation, the flags that are currently in the article work just fine. They show what a set of colors might look like in various forms of colorblindness, which gives non-colorblind people (and even colorblind people with other forms of it) some idea what happens with those kinds of colorblindness. Do they match up perfectly with my or someone else's colorblind eyes? No, but they don't need to, either. They'll illustrative, and they're never going to match any one person's eyes perfectly.

I personally think that the grey background images that were removed (now shown above) weren't very good. They don't illustrate any common colorblindness tests, and they don't simulate colorblindness for a non-colorblind person very well. I don't think they should be re-added. – Zawersh 13:31, 25 April 2007 (UTC)

They're a lot better than the ones we have now. The ones we have now aren't common ones with the rainbows, and the ones up there are better, we could just leave a note saying that those with the low frequency monitors or whatever won't see it. --64.205.199.7 14:18, 14 May 2007 (UTC)

I agree. We could just leave a note, I'm color blind (I'm sure the rest of you are, not to make myself feel special) and I find the one in the middle interesting considereing I cant see a bloody thing. --SurfingMaui540 23:19, 14 May 2007 (UTC)

I agree. I find it pointless that we would leave those ones in the article now. --LtWinters 21:29, 15 May 2007 (UTC)

Obviously, we all want it changed. I'm moving it back in. --LtWinters 22:59, 15 May 2007 (UTC)

No, we all don't want it changed back. If that were true, it wouldn't have been removed in the first place, and I wouldn't have voiced that I agreed with the removal.

You're each saying you think the grey-background images are better. Could you please clarify: what are they better for? They don't illustrate any real colorblindness tests. They don't simulate colorblindness. What point, exactly, do these images serve, and why do you feel they are better than the flags? I'm not exactly opposed to having them in there -- but I'm really not seeing that they add anything either, and I'm somewhat mystified that you all are so strongly advocating them. – Zawersh 07:06, 23 May 2007 (UTC)

Well, I think a lot of people wonder what people who are color blind do or don't see, and images that say "Someone with ___ can't make this out" are as helpful as ones that say "This is what ___ looks like to those with ___". To that end, I think both sets of images do serve a bit of a purpose, and it's nice to have a few more images to break up big blocks of text. I'd rather have images that are more in line with the picture at the end of the article (the tri/dichromat apple comparison), as I find that to be the most illustrative of how the condition affects real situations, but I think the other pictures do still add something. --Xanzzibar 13:16, 23 May 2007 (UTC)

I agree with Xanzzibar. I appreciated it for that reason (it is a valid test if not a commonly used one), and I'm sure people who are actually color blind (don't tell me they're irrelevant) would appreciate it even more. I have normal color vision and could easily make out the numbers on an LCD LUTted close to 1.8 gamma. The red 37 is blatant, the blue 83 slightly less so, and the purple 56 is faint but clear. Make sure you don't let colors clip by using broken brightness/contrast settings. If you do you voluntarily prevent colors from displaying correctly, and you shouldn't blame the image. A real problem with LCDs: without correction, whether done by the electronics in the monitor, the GPU, or software, the response curves tend to be rather weird.

Of course, if there's a quality replacement (that is, images with the same purpose) I don't mind; I'll leave that choice to the color blind or those who know how they are really perceived. --Jonathanvt 19:15, 23 May 2007 (UTC)

haha yes as I said.... most of us want it with those grey things...--LtWinters 18:57, 25 May 2007 (UTC)

• phew* and i thought i had all those diseases, when its just my lcd monitor. I can see 2 of the 3 numbers on the images here.(the Far Left and Far right). Seems a warning should be put on the image maybe to tell people that it may not work on a lcd screen. 219.88.78.200 20:25, 8 July 2007 (UTC)

Definitely. I was convinced I had tritanopia for a second until I tweaked the brightness. 86.137.77.251 03:21, 11 August 2007 (UTC)

My girlfriend and I viewed all three images on laptop LCDs. She said once she knew what she was looking for, she could see it: I still could not. Even after she traced it out. --76.243.28.8 03:57, 11 October 2007 (UTC)

These images suck. I'm not colorblind but they are way too subtle for anyone to reliably pick anything out from. What's wrong with the conventional high-hue contrast mesh of circles in a circle like this? --Belg4mit 16:40, 27 October 2007 (UTC)

I'm not colour blind, but on my laptop LCD, the 37 is clear, the 83 is hard to determine and the 56 is almost impossible to see. It's running at its native resolution, and even changing the brightness doesn't help much. -- Mithent 15:21, 10 November 2007 (UTC)

 Same here. #56 is junk. Find another.  —Preceding unsigned comment added by 75.42.82.54 (talk) 05:13, 3 December 2007 (UTC) 

Moved from article for discussion

Conversely, the board game Cosmic Encounter was designed and tested with colorblind individuals, and two of the player colors, a dark blue and a light blue, are difficult to distinguish by normally-sighted individuals.[citation needed]

I don't find the above notable. Isn't such testing commonplace? More importantly, hasn't this been a recommendation from design and human factors groups for many, many decades now? --Ronz 22:13, 21 December 2006 (UTC)

Speaking as a former program manager at a prominent software company, I can testify firsthand that testing for visibility by color-blind people is far from commonplace. I only wish it were more common.Conoisseur 08:38, 26 August 2007 (UTC)

Question for an expert

It is possible to possess both a protanomaly and a deuteranomly?Fistful of Questions 02:57, 29 December 2006 (UTC)

I would also like an answer. I can only see in the three basic colours, red, blue, green, and all mixed colours just look like the closest non-mixed colour, with the exception of some greens, oranges and browns (probably due to their very different brightness). I can't find this deficiency in the article, however I seem to be positive for both protanopic AND deuteranopic deficiencies. The test down the bottom, the circle of dots, I'm just going to say I can see both numbers, but very faintly.

So is it that it's possible to have multiple deficiencies, or one that's not on there or one I haven't read about yet? It's possibly my display, but I doubt it. I have taken tests before and know I come up with some strange results. ~Deadly-Bagel (talk) —Preceding comment was added at 13:12, 13 December 2007 (UTC)

History

Dalton was NOT the first scientist to publish a paper on color-blindness. Specifically, there is a paper from the 1600s in the Transactions of the Royal Society (in the 1650s or 1660s. I think). I'll try to find it again and change the article. David Manthey 15:47, 22 January 2007 (UTC)

GA Class

Looking over this article, it appears to have everything that is required of a GA article and more. Da54 23:11, 17 January 2007 (UTC)

external links

I believe there has recently been an overzealous removal of external links. I have been reading this article and related ones on color perception in the past few weeks. I find these articles lacking real, hard information. In particular, I can't seem to find pointers and references to books accessible to the general public. Actual research papers are very hard to read for the layman.

In the process, I looked at many external links. Some are not very useful, and many of them are. I finally found a free software similar to what I was going to write. It changes the entire screen on a computer to make colors distinguishable for color blind people. The external page also includes detailed information on how it enhances images via saturation, filtering, color transaction and hatching. I added the link to this article and it was promptly removed among half dozen others.

I am going to add it back. If you plan to remove it, please look at the external page first to make sure you understand what you are doing. I don't immediately see how WP:NOT prohibits inclusion of this link. Removal of this link does a color blind person a disservice.

Unlike the unremoved link to www.vischeck.com, this external page is free of advertisement and the software is free. I installed it last night and it worked really well. Fred Hsu 16:25, 19 February 2007 (UTC)

• The link was: Visolve, free software that transforms colors, enhances saturation and redraws colors with hatches for color blind people. It comes with a standalone program to capture/transform images on screen and a toolbar in Windows taskbar to transform the whole screen.

WP:NOT#REPOSITORY: "Wikipedia articles are not: 1. Mere collections of external links." The problem is that the External links section is becoming a link farm of tools related to color blindness. The External links section should be supplemental information that supports the article topic WP:External_links#What_should_be_linked. Instead we have sections of external links on testing for color blindness, simulating color blindness, designing for color blindness, and tools to help people with color blindness. --Ronz 16:51, 19 February 2007 (UTC)

(If you don't mind, I'm going to change the title of this section to make it more civil.) --Ronz 16:51, 19 February 2007 (UTC)

I changed the title of this section. Can you please post your thoughts to talk page, before you re-remove links in the future? I plan to enhance this article after I am done acquiring and reading books on this topic. Perhaps I'll have more intelligent things to say about this topic after I write the program I siad I would write. Until then, some of these external links are extremely useful and are logical extensions for readers of the current article. If I found it very useful during my research, I think other reader will as well. Even after the rewrite, I think many of these external links are still useful. And, can you please answer my questions on www.vischeck.com? Why was the free software removed and this commercial page left? I am not advocating for removal of vischeck; I found it useful as well. But I don't understand the logic behind your removal. Thanks. Fred Hsu 17:04, 19 February 2007 (UTC)

Thanks. I tried to make the change and discussions at the same time. Sorry about not answering all your questions. I went through the links quickly and they certainly could be trimmed further. My basic perspective on this is that this is an encyclopedia, not a place to find tools and tests. --Ronz 17:39, 19 February 2007 (UTC)

I beg to differ with your approach. If we simply remove all unrefernced material and all external links from wikipedia, it will be extremely hard for people to gradually build up good articles over time. Instead, we leave stub templates, fact-check templates and notes in talk pages, with the hope that someone will come along and fix these problems. Please see [edit diff of Mitochondrial Eve] for an example. This article was full of incorrect statements and unreferenced statements. People could have simply removed all such problems, leaving the article with maybe two paragraphs. But instead, stubs and fact-checks were added and discussions started on the talk page. Eventually, someone thought it was time and rewrote the article.

You quickly went through links and removed those "you" deemed inappropriate. In the process, you probably removed some weeds and you also threw away jewels. Some good pointers useful for later editors are now gone. The external link section in wikipedia articles are really not part of the article. They are supposed to be pointers to readers who are not satisfied with the current state of the article. In time, they will become part of the wikipedia, with help from other editors.

As for tools, we live in the information age. Wikipedia is so much better than Britannica in part because it has interwiki links and external links to pages outside of wiki. After reading wiki article on Color Blindness, many reader would want to either try the dichromat experience or find software to help them cope with this condition. If they can't start their search here, where do they do that? Based on 'your' basic perspective, all links in external links section should be purged, because they are all links to tests and tools. Can you please explain 'how' you decided what to purge and what not to purge?

I am restoring the particular link I mentioned here. Please do not remove it unless you come up with better excuses. Thanks. Fred Hsu 19:52, 19 February 2007 (UTC)

Please be more civil in your discussion here and your edit summaries.

I'll remove items as I see fit, referring to the relevant guidelines when I do so.

It's the editor adding the material that is responsible for supporting it's use in the article. --Ronz 21:11, 19 February 2007 (UTC)

After my research, I may be able to write new articles on color blindness testing, simulation and tools which help color blindness people into separate articles. Then add sections in the Color Blindness article which point to these new articles. Until then, I believe these links should be kept in the external links section to help people expand this topic. Instead of simply removing all of them, you can also add cleanup templates or something to that effect. Or, create stub articles for these sub-topics and move links there. If you are simply reducing the number of links to some manageable set, I believe you need to be more careful with your selection of links (see my thought on Visolve vs Daltonize (vischeck). You can't just cite generic WP:NOT and WP:EL as reason for removal of this link, while not applying the same principles to all other external links. Fred Hsu 21:45, 19 February 2007 (UTC)

I went through all the links and removed the ones I thought were extraneous and in violation of NOT and EL. I didn't remove them all for the very reasons you give. I reluctantly left vischeck in because it has online versions available. I tried to find a better link to the online versions, but couldn't fine one that I thought would work well on its own. --Ronz 22:44, 19 February 2007 (UTC)

I somewhat agree with both Ronz and Fredhsu: The list of softare links is inappropriate for this article, however, they are not inappropriate for Wikipedia. Take a look at genealogy software and genealogy. Rather than make a link-list at the end of the genealogy article, the software products were turned into an article of their own right. I think the same should be done here. Create an article that discusses software solutions that have been developed to deal with or work around colorblindness. Include links in that article, and possibly create articles for some of the specific software products themselves if they are notable. I think an article on software solutions for colorblindness could have more potential than the geneology one, too, if it includes things such as discussions of the algorithms used and the techniques applied in the software. -- – Zawersh 12:24, 1 March 2007 (UTC)

I don't think genealogy software would stand up to an AfD from my experience. Still, I think it's worth pursuing the suggestion to create a new article on software solutions. --Ronz 16:11, 1 March 2007 (UTC)

I'm an absolute beginner as editor and I didn't notice the existence of the discussion page and the external link topic in it, so I just readded a link to the Accessibility color wheel. In my opinion it is still a valid link but if anyone wants to remove it again for the above mentioned reasons, it's ok --Gmazzocato 12:11, 30 October 2007 (UTC)

Thanks for taking the time to comment here. I've removed it. If you haven't already noticed, you have your own discussion page User talk:Gmazzocato where I had previously given you information about Wikipedia and editing. --Ronz 16:08, 30 October 2007 (UTC)

Proposal: Type and Color from Joe Clark's accessibility book.--K. 11:24 12 Mar 2008 (CET) —Preceding comment was added at 10:25, 12 March 2008 (UTC)

Monochromacy

In one section, certain symptoms (e.g. nystagmus) are associated with rod monochromacy, and in another they're associated with cone monochromacy. I haven't a clue which is correct, but someone should fix this. /blahedo (t) 14:59, 12 March 2007 (UTC)

Disability

I think more should be disussed on the nature of the disability. Why not as apparent as other issues Color blindness can preclude an individual from many careers. I myself realized this when I joined the military and despite the plethora of jobs, i was availed just two. Color blindness can effect education aswell.--66.30.196.201 05:29, 28 March 2007 (UTC)

Rainbow Errors?

On the tritanopia vision rainbow flag, there is blue, but that is the disorder with the absence of blue photoreceptors right? Can someone help me out on this? —The preceding unsigned comment was added by Kyle112 (talk • contribs) 13:24, March 30, 2007 (UTC).

Also in the RGB article there is a neat picture series with a barn, I'd like to see something like that viewed through the eyes of different color blindnesses. —The preceding unsigned comment was added by 75.30.219.118 (talk • contribs) 20:35, April 3, 2007 (UTC).}

DakeDesu: The rainbows are inaccurate. I suffer from a Red Green colour deficiency, and _all_the rainbows look completely different--on top of that I can distringuish the colours in them. Mind you, I don't match the colours the same as you say the colours are, but they are _extremely_ inaccurate views on colour deficiency.

If it is any importance, I am running version 7 of X.org, running Firefox on KDE() and GLX on Savage Card (CRT Monitor)

I agree; those of us that are affected shouldn't be able to tell the difference between the control and the rainbow that reflects our condition. Being color-blind I can't tell you WHY it's not right...I just know that it isn't!doctorwolfie 19:20, 4 September 2007 (UTC)

Not sure why, but the original LGBT flag isn't showing up right now... Not sure how to fix it... soldierx40k (talk) 22:17, 26 November 2007 (UTC)

Traffic lights

The article mentions that red/green colour blindness makes it difficult to distinguish traffic lights by colour; in the UK - and presumably throughout Europe the green light has added blue so it looks quite different from the red even if, like me, one is red/green colour blind. If anyone has a reference to confirm this (ISTR hearing it on the radio once) then shouldn't this be in the article?

Apepper 22:53, 30 March 2007 (UTC)

• I know for a fact that in the United States (at least) one of the lights (I forgot which, I'll do research) appears brighter to colorblind individuals. Kevingamer 01:08, 10 April 2007 (UTC)

Last I heard, the main cue in traffic lights that color blind people were supposed to follow is position - which light is on. --Ronz 01:13, 10 April 2007 (UTC)

That's probably true, but I can't distinguish red/green LEDs but I can easily tell the difference between red/green traffic lights. Apepper 16:46, 16 April 2007 (UTC)

The traffic light article has some mention of colors added: "Usually, the red light contains some orange in its hue, and the green light contains some blue, to provide some support for people with red-green color blindness." It is not cited, though. They also have a picture of a traffic light in Nova Scotia that uses special shapes to help color blind individuals. – Zawersh 00:39, 12 April 2007 (UTC)

Here in the Netherlands the green light tends to be a bluish green. No reference, sorry, maybe I'll look for that when I have more time. --Jonathanvt 19:18, 23 May 2007 (UTC)

As a colorblind individual in the US, I can confirm that 1. It's hard for me to distinguish the yellow light from the red light and 2.) the green light actually appears to be white. The only thing that saves me is I know its red, yellow, green. However, that doesnt help when it's a single blinking yellow or red light, I never know whether to stop (blinking red) or slow down (blinking yellow). Tjshome 20:05, 6 November 2007 (UTC)

Excuse me for this possibly stupid question but can't you tell which light is it by its position (i.e. the higher one means stop, the lower one means go?) 194.90.37.111 (talk) 19:33, 31 March 2008 (UTC)

Most of the time you can (this is how I look at traffic lights), but this can be hard in some situations, like fog, or with horizontal lights. At night it can also be very difficult to see enough of the traffic light assembly to know which position is on. My grandfather also told of one state (which escapes me now) where the lights were reversed. I'm sure this is no longer the case, though. 76.104.173.177 (talk) 21:51, 1 April 2008 (UTC)

Treatment?

There was a treatment for red/green colour blindness introduced a few years ago using a single coloured contact lens - should this be described; not by me I know nothing about it! Apepper 22:55, 30 March 2007 (UTC)

This is mentioned briefly under Color blindness#Treatment and management, but could certainly be expanded. The specific treatment you describe has been around for at least ten years -- I tried it for a few days back sometime in the mid to late 90's. One of the contacts had a red dot on it. I only have minimal anecdotal knowledge of it, which doesn't really qualify me to write about it either. :) – Zawersh 00:47, 12 April 2007 (UTC)

I had one of those in medical school; you can do the same thing with any lens (or piece of glass, plastic, etc) that is the color that you have trouble with. For example, a person with red-green color confusion can look at an object using a red lens. If the object is red, then it will appear "bright" through the red lens. If the object is green it will appear "dark" through the lens. It doesn't really correct the vision; it just gives you a trick so that you can figure out what color something is. It doesn't work with muted tones, because the white that is added into the color (to mute it) causes either color to "light up" when viewed through the lens. It helped with H&E stains though.doctorwolfie 19:27, 4 September 2007 (UTC)

Dyschromatopsia

"Dyschromatopsia is a symptom associated with the eye. Strictly refers to a disorder/change in colour vision." This was requested to become an article, however I believe it would be more suited if that sentence above was placed somewhere within this article. I wanted to place it somewhere, but I felt I leave it to someone with better judgement as this is a "Good Article". Then I will make a redirect for Dyschromatopsia into this article. Sounds good?(SORRY forgot to sign) petze 12:23, 1 April 2007 (UTC) Oh and PS, here is a refference for it: http://medical-dictionary.thefreedictionary.com/dyschromatopsia petze 12:27, 1 April 2007 (UTC)

ACTUALLY Dyschromatopsia is A AKA FOR color blindness. Omg how stupid of me..... I will add Dyscromatopsia as a AKA to color blindness and add the disease db on the info box and of course if anyone objects please discuss it with me. I shall also place a redirect for dyshromatopsia into color blidness. OMG i keep forgetting to sign...sorry petze 15:45, 13 April 2007 (UTC)

Dang...

Wouldn't that suck to have that. But wouldn't you not know if you have that condition if you were born with it since you would never know that you're vision is wrong?--Eloc Jcg 20:19, 14 April 2007 (UTC)

You'd figure it out over time when the rest of the world gives two or three different names to the exact same color, insisting, "That's not the green one, you idiot, that's red! That's the green one!" pointing to one that looks identical. --205.201.141.146 20:28, 27 June 2007 (UTC)

Benefit to Dichromacy?

Dichromacy and other forms of 'colour blindness' are much more prevalent among humans than other primates. It is likely that we are under much reduced evolutionary pressure, what with our food-sharing practices, which are rare in other animals, and this may explain it. However dichromacy occurs in other primate lineages as a norm (trichromacy is derived, and not as frequently as we would expect); it has been suggested that there may be benefits to dichromacy, such as the ability to 'see through' red-green camouflage.

Are there really such benefits to those who are red-gree colour blind (or other differences in vision)?

I think it may be worth mentioning in the article also that many organisms have up to 12 different colour photoreceptors (some shrimp... I don't have a ref to hand. Sorry); birds have 4 etc. It's important to realise that the number and response spectra of colour receptors are simply different ways of coding the reflectance spectrum of objects in the visual field; colour blindness is not 'wrong' or 'deficient' vision any more than 'normal' human colour vision. Trichromats are just as much lagging behind the colour vision of other animals, who have a very different and extended rainbow.

Also, should there be a link somewhere to Colour Constancy? —The preceding unsigned comment was added by 131.111.8.97 (talk • contribs) 10:28, April 20, 2007 (UTC). color blindness is alsowhen someone sees something in red and you see it in all different colors. There is many types of color blindness there is red color blindness there is shade color blindness there is black and white color blindness there is also color colorblindness. welllHie I am not here i love Gerard Way.

Old Pictures

What happened to the old pictures (last time I chicked war 6 months ago) that had the numbers and a gray background and those who were a certain type of colorblindness couldn't read them? They are much better than the ones we have now, I would know as I am colorblid (as I'm sure many of you are too and also have an opinion, whether it be contrasting to mine), and those who wish to test themselves for colorblindness would find this fun and would get more viewers to the website. --24.225.156.40 00:24, 25 April 2007 (UTC)

There's some discussion regarding this above in the section Regarding the Sample Images. – Zawersh 12:55, 25 April 2007 (UTC)

Colorblind image template?

I'm red-green colorblind, and have on numerous occasions found images on Wikipedia whose colors were hard to fully distinguish (like this one). Have other people encountered this problem? If so, would a template for such images be appropriate?

--69.118.136.65 19:54, 9 June 2007 (UTC)

Such a template exists on Commons since yesterday: Commons:Template:Color blind. I hope people find it and start using it. Samulili (talk) 06:19, 15 May 2008 (UTC)

Prejudice against colorblindness

Can't see an existing place to put this but perhaps someone who cares about this page might make a space.

http://www.aopa.com.au/infocentre/topicdocuments/colourvision.pdf

Colorblind individuals have been haphazardly excluded from aviation work for years without any scientific basis.

Doesn't add up

If 10% of men have some sort of color blindness, how can only 1.3% of the US population be color blind? I find it hard to believe that American are that much less likely to be color blind than the rest of the world. If the 10% number is correct than it should be closer to 5% of the American population. Hichris 17:18, 24 August 2007 (UTC)

This should be featured.

Just came to read up on this article,, and I see no real problems in it. It gives pretty much a flawless description of the whole thing, has attractive images, and while it doesn't have a whole truckload of references, it has enough reliable ones to justify FAness, I think. How d'you ask for something to become featured? AR Argon 05:14, 26 August 2007 (UTC)

Given a closer look at the article, it needs a quite a few more references, though everything else is practically flawless. Am I the only guy who wants to work at this article? AR Argon 22:28, 31 August 2007 (UTC)

There's a neat text "Color Vision; from Genes To Perception; edited by Karl R. Gegenfurtner and Lindsay T. Sharpe" which is a wealth of reference material. There was also an excellent article in Science ("The Chemistry of John Dalton's Color Blindness; Science Feb 17, 1995; 267;984-988)...how many references would you recommend?doctorwolfie 19:33, 4 September 2007 (UTC)

Question from reader's point of view

I cannot read the number 49 in Image:Colorblind4.png, but I can see:

• the Roy G. Biv in Image:Gay flag.svg,
• the 37 in Image:Colorblind3.png,
• the 56 in Image:Colorblind5.png,
• the 74 in Image:Ishihara 9.png,
• the red in apples....

Does that mean I'm colorblind in some form? Because, if I can see the other images and not just Image:Colorblind4.png, that leaves me very confused...I've even tried setting the brightness to very high and very low....I all I know is that I'm particually sensitive to bright light and bright colors, but not to an extreme.....THROUGH FIRE JUSTICE IS SERVED! 15:55, 16 September 2007 (UTC)

In fairness, the "49" is extremely subtle. This is just as easily caused by an uncalibrated or low-quality display (including an LCD set to a non-native resolution or anything below 24-bit color). In effect, a display can itself be "color blind" by having an insufficiently wide or dense gamut. Standardized tests in print are more reliable.

If you still can't see anything regardless of display settings, you may be mildly deuteranomalous. This is probably nothing that you'd notice in real life; only a standardized test might show that you are slightly worse at distinguishing unsaturated greens and reds than the average observer. 82.95.254.249 01:20, 21 October 2007 (UTC)

Regarding the apples

Regarding the apple simulation, I find one of the most confusing part of being colorblind, the so called simulations.

I have a deuteranomaly (I think). Yet I see a clearly red apple at upper left of the simulation. The apple looks (in terms of color) nothing like the apple on the right. The text states that the simulation applies to trichromat, which I gather I am. No quite into the technical terms.

Is the simulation wrong, or am I getting it wrong? Cypres 21:11, 16 September 2007 (UTC)

One of the possibilities is that the simulation gives you a double douse of color deficiancy. For example, If see greens that are half as bright, then an accurate simulation would appear only to have 25% green to someone with that type of color blindness

24.237.218.205 (talk) 02:59, 16 February 2008 (UTC)

Regarding camouflage spotters

The article reads: "Anomalous Trichromats are often able to readily spot camouflage clothing, netting, and paint that has been designed for individuals with color-normal vision. For the same reasons a color-blind painter might use too much blue to paint a green foliage landscape, a similarly color-blind artillery spotter would perceive too little blue dye used in camouflage created to match the same landscape."

Wouldn't this same artillery spotter see the landscape as having less blue dye, too? It seems entirely logical that if he perceives the clothing as having less blue dye than a color-normal person would, he would also perceive the landscape to be that way, giving him no advantage. I was under the impression that the advantage a color-anomalous person would have would be that the color-anomalous person would be better at picking up on texture and shape cues and not be as used to relying on color, thus not allowing his visual system to be fooled as easily. —Preceding unsigned comment added by 165.123.166.155 (talk) 14:52, 30 October 2007 (UTC)

I think the reason that colorblind marksmen have the advantage is that we rely more on processing shapes, rather than color. As in any disability one compensates for the skill that one doesn't have.doctorwolfie (talk) 11:44, 29 January 2008 (UTC)

"Causes" Section

In the "Causes" section, the first sentecnce of the second paragraph is:

The different kinds of worlds will end and the human color blindness result from problems with either the middle or long wavelength sensitive cone systems, and involve difficulties in discriminating reds, yellows, and greens from one another.

That sentence makes very little sense, especially the first part -- "The different kinds of worlds will end" This looks like vandalism? Or something weird going on! Can someone who is knowledgeable about this topic fix the sentence? Watercat04 (talk) 20:03, 15 December 2007 (UTC)

I have an issue with the causes section also. The beginning line in the third paragraph states, "When color blindness is inherited (which is almost always the case), it is inherited from the X chromosome." seems to be misleading. To my understanding, this is the case with common red-green color blindness, but it is not always the case for colorblindness in general. Blue-yellow colorblindness does not follow this rule. Although I am not sure if [1]is a reputable source, I believe it to be correct. It states, "Blue-yellow color blindness can be observed only very rarely. Different studies diverge a lot in the numbers but as a rule of thumb you could say one out of 10′000 persons is affected at most. In contrary to red-green color blindness tritan defects are autosomal and encoded on chromosome 7. This means tritanopia and tritanomaly are not sex-linked traits and therefore women and men are equally affected." This contradicts the statement from the causes section. If someone could revise the statement in that section to clarify how color blindness can be inherited, that would be great. 72.55.216.82 (talk) 00:17, 23 March 2008 (UTC)

Neutral colours given as nanometre figures only... not good.

Is there some easy way of getting hold of a good basic guide as to what actual colours these numbers represent? I've played with spectrophotometers before and I'm still not super hot on how red/green/blue a particular number is, the average layperson reading this will be stumped and the containing statements will convey little useful information. If a person with a certain colour blindness cannot distinguish a pure light of 498nm from white light, what does this actually mean? What colour does that represent, and does it effectively mean they are seeing white "as" that colour? (Same as my seeing the pale orangey-yellow of my cheap 9w energy saving bulb as "white" on the various pieces of paper in the room where I am sat thanks to habituation and expectation, but if I concentrate on them, and compare them to the near-neutral white of the laptop backlight, it's easy to see the error). 82.46.180.56 (talk) 00:44, 17 April 2008 (UTC)

That's pretty much green; I labeled it. Dicklyon (talk) 01:23, 17 April 2008 (UTC)

Apple Pictures.

I looked long and hard at the apple pictures near the bottom of the page. I'm fairly certain the 2 "different" pictures are exactly the same, they just have the color channels changed (the core star and glare are the 2 most obvious identifiers. Even if great care was taken to set up different apples the exact same way, they wouldn't cut exactly the same or reflect exactly the same).74.167.173.21 (talk) 02:34, 6 May 2008 (UTC)

Well, it does says it's a simulation. It would be nice to know exactly what was done. Dicklyon (talk) 03:35, 6 May 2008 (UTC)

Yes, they're the same picture. The colors given by your monitor are a simulation of what a camera sees, what your camera sees is a simulation of what you see, so I don't see anything wrong with interpreting the color data to simulate what a colorblind person sees. It looks pretty much like the deuteranope simulation created by the Vischeck program: [2]. For protanopes the red (left) apple is much darker than the green (right) apple. You should probably mention this in the article; protanopes will see the image and say "that's not what I see". -- Madeleine ✉ ✍ 00:49, 23 May 2008 (UTC)

Ishihara tests biased?

I'm a deuteranomalous trichromat. I never knew something was different with my color vision until I was tested in school. If it were not for those tests, I would probably have gone through life without ever knowing. Suddenly I found myself barred from a number of occupations, and since then I've considered myself slightly disabled when it comes to vision. But after reading this article, I can't help wondering...

The question that has been nagging me is this: Do we, for a fact, know that it is not possible to construct an Ishihara like test that a deuteranomalous person can see, but not one with "normal" color vision? Has anyone ever tried? In other words, is the color vision of a deuteranomalous person really inferior to that of a person with normal color vision, or is it merely different? Is it possible that the Ishihara tests are biased for normal color vision?

After all, it wouldn't be the first time in history that those who differ from the majority is considered "defective" without any real basis for it. If you test motoric skills by putting a right-handed tool into the hands of a left-handed person, that person will indeed appear to be less skilled than others. And until recently, left-handedness was considered a disability. --Maggu (talk) 18:04, 21 June 2008 (UTC)

And, after a little searching, I found an article that seems to support that it would indeed be possible to construct such a test:

http://www.nature.com/news/2005/051205/full/news051205-1.html

--Maggu (talk) 19:39, 21 June 2008 (UTC)