A lot of people think, if you suffer from color blindness you can not see any colors at all apart from black, white, and shades of gray. But they are wrong.
This form of complete color blindness is a very rare subtype of color vision deficiency among much more common ones like the the well known red-green color blindness. You might say, in this case the wording color blindness isn’t chosen appropriate—and you’re right.
Color Blindness begins when you don’t have normal human vision which might be only a very light change of color perception. And it ends with complete color blindness combined under the umbrella term monochromacy.
If you are suffering under monochromacy, you perceive everything just in shades of gray. This makes it really hard to accomplish many everyday tasks, because colors are such a central part of our life. For example, people suffering form monochromacy might mix up the following colors:
- green and blue
- red and black
- yellow and white
Monochromacy—also referred to as monochromatism—can be observed in different forms and even worse, many different names are in use:
- rod monochromacy: typical or complete achromatopsia, total color blindness, day blindness
- blue-cone monochromacy: S-cone monochromacy, incomplete achromatopsia
- cone monochromacy: complete achromatopsia with normal visual acuity
- cerebral achromatopsia: atypical achromatopsia
Before we dig a little deeper into the different forms of complete color blindness you should know the basics of vision and specially color vision.
The human eye has two different receptors inside the eye to perceive light. They are called photoreceptor cells. The rods are very sensitive on brightness and used for night vision. On the other side we have three different types of cones (trichromacy) which are responsible for colored day vision. The three different forms of cones have different peaks on color perception: red, green and blue. And the mixture of those three base colors makes us perceive such a huge variety of colors—or at least almost all of us. Compared to cones, rods play no role in color vision.
Rod Monochromacy
In this case your vision relies solely on the rods and the cones are usually not working at all. Some cases also report that the cones are absent, have some irregular distribution or that they show abnormal shapes. Occurrences are estimated to be between 1 : 30,000 and 1 : 50,000. But even if this numbers look very small, rod monochromacy is still by far the most common type of complete color blindness.
Rod monochromatism is often referred to as achromatopsia and is based on autosomal recessive inheritance. In other words, you need two defective chromosomes and it is equally distributed among men and women. Achromatopsia is characterized by the following symptoms:
- complete inability to differentiate colors,
- severe light sensitivity (photophobia),
- long-sightedness,
- involuntary eye movements (nystagmus),
- and central depressed vision (scotoma).
Also rod monochromats are completely colorblind, they often learn to associate certain colors with objects and to differentiate some colors by their brightness.
Blue-Cone Monochromacy
This rare form of monochromatism is caused by loss or rearrangement of the genes encoding L- and M-cones. Because of that only blue color receptors (S-cones) and rods are transmitting color and/or brightness information. If you suffer S-cone monochromacy your are usually completely colorblind. But in twilight situations—where rods and S-cones are working—color perception can be compared with dichromatic vision.
There are reports about very different forms of blue-cone monochromacy and it is sometimes not easy to differentiate it from rod monochromacy. No exact number of incidences is available. Scientists estimate the frequency at 1 : 100,000—for men. Because red and green cones are encoded on the sex chromosome, inheritance patterns are similar to red-green color blindness. Occurrences in women are unknown.
Cone Monochromacy
Also known as complete achromatopsia, this form is very rare. Only a few cases have been reported and none of them is fully accepted. It is assumed that they are either have working L- or M-cones and inactive or absent S-cones. Compared to blue-cone or rod monochromacy, cone monochromacy doesn’t have reduced visual acuity or any special light sensitivity.
Cerebral Achromatopsia
In this case optical examinations show normally functioning cones and rods. It is not understood in detail yet, but it is thought that the color receptors are working properly only the information is not reaching the brain or is not processed. Only a few cases have been investigated. Cerebral achromatopsia is unlike the other types of monochromacy not inherited but and acquired color vision defect. It may be caused by trauma or illness.
The academical background and many references on all types of monochromacy can be found in Opsin genes, cone photopigments, color vision, and color blindness by Sharpe et al. An internet information portal on achromatopsia is provided by the The Achromatopsia Network.
My son has been diagnosed with Blue-cone Monochromacy… I am a bit confused…. Can he see some colors or is he completely colorblind? Thank you for your time.
Adrienne, in the eyes of a person with normal color vision, he is unfortunately completely colorblind. With blue-cone monochromacy he still has one type of cones available, but they won’t give him enough information to get a colorized picture. He will be able to distinguish at maximum a handful of different hues. Compared to normal color vision with more than one hunderd different hues this is almost nothing. He will make his color judgment almost solely based on brightness.
I wish you and your son all the best on your way. Try to connect with other people suffering the same, so you can exchance experiences. You might like to start with the achromatopsia network.
Hi there,
i have recently been diagnosed with Rod monochromatopsia following about 6 comprehensive eye examinations. I have virtually no colour vision left following an accident which apparently has destroyed the part of my maclia which enbles me to see colour. ??(if this is the correct word) I have been told i can do nothing about it and will have to live with it. I cannot seem to get any answers but i found this website. Can i do anything??? can i be helped at all? I have seen these companies who offer colour vision enhancement contact lenses, but there are only 4 i can find and for 2 of them you have to travel to hungary or america. can you help any explain how i can obtain any of these lenses.
Many thanks
Christian Wilson
Christian, thanks for sharing your story with us. Just a short note: It is either called monochromatism, monochromacy or achromatopsia.
Unfortunately I have to tell you that no color enhancing lenses can help to improve your color vision. This contacts can only shift your color perception and can’t really improve it.
So if you can’t see any hues anymore there is no system to feed this information back to your brain. There is only one possibility that time could maybe heal it and give you back some better color vision. But there is also only little chance for this.
I wish you all the best. Regards, Daniel.
Hi!
I would like to share with you amazing works from a world know artist which suffers from achromatopsia.
you can GOOGLE or YAHOO his name.
his webpage is:
http://www.jaylonewolf.com
the latest press release is announcing his new exhibit in miami, florida. Oct 31st.
contact me for additional info.
Hi Adrienne, I have bluecone monochromacy, I didnt know till i became a teenager, I am glad you have found out for your sons sake, life will be easier to understand knowing what the difference is, sadly, with the understanding, comes realization, but, at least we are not blind. Be thankful for that sight we have. A unique perspective of life he has been given. They say its not a disability, he will laugh at that. focus on an education that doesnt rely on color sighted needs, I have had many opportunities doors shut in my face. With planning you an he can avoid that. Good Luck, feel free to contact me anytime if you have a question, not that i have any answers, Todd, Valerk8@hotmail.com
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Hi, my husband is completely color blind but we are not sure waht it is called… I didn’t believe him because I had never heard of it. Now that I have researched it a lot of his behavior makes sense, like his love for pandas and his hate of myself wearing face powder. Is there anything we can do to reduce his light sensitivity???
I have a question. Are all forms color blindness located on the X-chromosomes? I’m not talking about the diseases that lead to Color Blindness (i.e. Retina Pigmentosa) . I just want to know if the Genes controlling color perception are all located on the X-chromosome. Thanks:)
Peter: No, they are not only located on the X chromosomes. Have a look at the article Chromosomes involved in Color Blindness to learn more about this.
Hi,
My father in-law is totally colour blind, though I don’t think he’d ever get tested. He squints a fair bit in the sun, but seems to have a great eye for detail. Hasn’t stopped him being a boiler-maker, then owning an engineering company, then designing feed-lots, then selling farms (drives a crazy number of km’s in a year). It’s always a laugh when he comes back having bought a few new shirts though (I think the shop assistants take the opportunity to unload stock that could sell to no one else)… My wife is also colour blind, but only slightly. She only has trouble with colours that are very dark, or very light. I’ve been told that any boys we have will be colour-blind. Whats the chances that it will be extreme like my father in-law (sounds pretty unlikely), or nearly insignificant like my wife (except for those darn numbers in dots that drive her nuts. Sorry beautiful, it’s not 24… it’s a boat…)? All her brothers who have been tested are also colour blind (family of eight), as well as one of her sisters. No colour blindness in my family.
Ben, only red-green color blindness is encoded on the X sex chromosome. So if you are really talking about some form of total color blindness, I can’t really tell you what the chances for your children are.
But as it looks like it doesn’t really matter any way – your father and your wife seem to get a long very well.
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Love the site. As a pretty severe red-green color weak guy one of the most frustrating aspects is attempting to explain to others what things look like. Any additional comparison images would be very very helpfull. Thanks!
My son has blue cone monochromacy and he will be turning 16 soon. He is watching all of his friends get their driving permits and licenses. His low vision and color blindness has never had such an emotional effect on him until lately. With yesterday’s news of the successful gene replacement therapy in the 9 year old boy, I have been searching the internet all day today looking for a clinical trial for my son. I was able to read that a trial for achromatopsia is going to be open soon. Will blue cone monochromacy qualify for the achromatopsia trial? Also, if you know of any blog specifically for BCM, could you please forward me the link?
Any parents with children diagnosed with this disorder can feel free to contact me directly through email at hdanna@uninets.net. I was told that this is a disorder that has only been linked to my family; therefore, I’m guessing that if we did the genealogy, we may discover that we are related.
My son was involved in a traumatic brain injury 2 years ago.
At first all colors were very bright and then everything faded to black and white and has been that way ever since. It has been mentioned that he may suffer from Cerebral Achromatopsia, but so little seems to be known that they don’t even feel comfortable giving that diagnosis.
Any information that we can obtain, especially as it may relate to him some day getting his color vision back, would be greatly appreciated.
My mother was born completely color blind and legally blind. Is this the same thing. Her sister a year older then here has the same condition, they are the only 2 out of 5 kids (with one being a boy) in the family with this. Neither parent are color blind. My mother has never given me a diognosis of her sight, she gets upset. Any help??
Hi, I’m suffering from monochromacy. ever since i was born i’ve been completely color blind and sometimes it’s difficult at school when no one belives you. And it’s mostly because i’m completely color blind, and im a girl. So no one except teachers belive me. Not only that but people don’t stop asking me what color do i see. it’s so difficult. When I got the color correcting lenses, I used them and I passed a “color test”(thats what i call it) becuase they showed me a card with a color on it and I had to identify it, when i started these lenses, i got every color right, but without them i can only see in black and white. I am so thankful for these lenses and I’m thankful for not being completly blind at birth.
Hi!
I have a father and a son with Blue Cone Monochromacy, and there’s a few other males with it in our family. So, however much I wouldn’t wish it on anyone, I am delighted to have found other people in the same boat here.
However, I am a bit taken aback a bit with the answer given to the question relating to how people with BCM see colour.
In fact the blue cones can only interpret the blue rays of the light spectrum. Therefor instead of seeing life in colour, or in black and white, it’s all in shades of blue. That is why for example people with BCM struggle to see blue ink on white paper: the paper looks equally blue.
They seem to be able to categories some colours pretty consistently, though. In our family it is obvious there are three ranges: “blue, white and pink” appear to be much the same, “orange, yellow and green”, and then “brown, black and red”. As within these groups the colours look much the same (yellow is often recognised correctly for some reason it has to be said)there is no contrast between them. That’s why for example the red traffic light is hard to see: red on black background.
I wonder if this fits with the experience of the other people on here?
Anneke
I was diagnosed with Blue Cone monochromatism several years ago. I can see colors just not in the same way as others. One main thing is it is hard to read blue writing on white paper, yet I can read yellow on white, but it doesn’t really slow me down. When I ran across this site with the simulator I thought it was a pretty cool site and have sent it to a few people.
Thanks,
Ryan McCary
iam doing a paper on color-blindness.and i thouth this place is realy cool!
i’m not colour blind, but i have a friend who doesn’t seem to fit any of the descriptions above. he has exceptional night vision, but is not sensitive to daylight, has no problem with detail, and the only colour he can perceive is orange. he says it “glows.”
as an artist and all-round geek this fascinates me. have you heard of this phenomenon, or could there be a combination of different conditions that could explain it?
Fiona, thanks for sharing this description of your friends vision. – There are definitely to many phenomenons we don’t really understand yet and this sounds like one of them. Only a visit to an eye specialist could help you and your friend to understand this phenomenon in more detail.
I know that Rod monochromats can see espceially well in the dark, is this the case with cone monochromats?