Color Blindness in One Eye

Is it possible?

I was watching an episode of Ink Masters and one of the artists claimed to be “partially colorblind.” That sounds like a cop out - I think is just straight up color blind - but made me wonder if it’s possible to be "partially colorblind and the only way that seems possible is if one is colorblind in only one eye.

I repeat, is it possible?

Perhaps a genetic mosaic condition where one eye got the colorblindness gene(s) and the other didn’t? IANA medical professional or biologist, I’m guessing based on layperson knowledge largely gleaned from Wikipedia wandering.

Did the artist say that they were color blind in one eye? I would interpret “partially colorblind” to mean that they can see some colors but don’t have the full range of normal color vision, which is quite common. Total color blindness (monochromacity) is actually quite rare.

There are several different types of color blindness, and as @markn_1 says, total color blindness is pretty rare. My guess is that the artist describes themself as ‘partially colorblind’ because most people assume color blindness means strictly black and white.

Agree w @markn_1 The OP is (probably) confused about what the artists meant. There are lots of kinds of color blindness and also degrees of color blindness within each kind.

Here’s a jillion words for the OP to learn more about it:

The very first section “Effects” has some nice sample pictures that show what most people mean by “color blindness” is not the absence of color perception, but rather is reduced (and somehow skewed) color perception.


I have red-green colorblindness. I can’t distinguish between certain values (brightnesses) ** of red and green.

It’s the same in both eyes.

** I have no problem with traffic lights. The values are chosen to be easy to distinguish for people with this fairly common colorblindness.

The most common version of color blindness is red-green color blindness. Such a person cannot distinguish between red and green (nor yellow, which is a mix of the two), or has a difficult time distinguishing between them, but can still tell the difference between red-yellow-green and blue as well as anyone else can.

I think that blue-yellow colorblindness also exists, but it’s much rarer, and independent of red-green. And the only way a person would be completely colorblind would be if they coincidentally had both colorblindness versions.

Regardless of how that artist is actually colorblind or not isn’t the point, though. It just made me wonder if my example is possible – colorblind in only one eye.

Mr. Google’s AI gave me some half-correct crap (as usual), but once I got past the bullshit generator and into the search results Google found this for me:

From here: Is It Possible To Be Colorblind In One Eye Only? - American Academy of Ophthalmology

The cite given is by a medical doctor with a specialty in Comprehensive Ophthalmology.

Actually, this is something that I’ve wondered about for a while. As I understand it… Genetic mosaic conditions are actually incredibly common. Almost all women have a genetic mosaic condition… with respect to the X chromosome. Having two active copies of the X chromosome would cause all sorts of problems, and so in each cell of a woman’s body, one of the two Xs is deactivated. Which one is deactivated is randomly determined for each cell, but it happens relatively early in embryonic development when there are only a few cells, and descendants of those cells keep the same X deactivated as their ancestor, so a woman’s body is a patchwork of splotches where one or the other X is deactivated. These splotches are of such a size that it should be quite reasonable for one eye to have one X active, and the other eye have the other one.

And yet, female carriers of colorblindness, which is carried on the X chromosome, typically have normal color vision in both eyes. Why is that? Why don’t they ever have one, or even both, eyes, where the active X is the one with the colorblind gene? Or is colorblindness due to some hormone or something produced elsewhere in the body, not in the cells of the eyes themselves?

Also, the red light is required to always be on top (or on the left if it’s a horizontal signal)

With one exception in Syracuse NY. Only one exception in the entire world according to the article. However, they are short on details explaining how that was determined.

It’s my understanding that X inactivation is finer grained than that, so for an XX carrier of the red/green color blindness gene, half of their color receptor cells will have the wild type gene, and half will have the mutation. That is still adequate for color vision.

I don’t know enough about X inactivation to square that with calico cats, except to say that eyes \ne skin, and humans \ne cats.


If anyone has a serious accident due to the misplacement of the traffic lights, Syracuse is in for a world of hurt. I’m surprised no one has tested this already.

There has been noise about changing it. Don’t know if it’s led to any serious accidents.

Yes, it’s possible to be colorblind in one eye and not the other but it’s very rare. I did have an internet acquaintance who claimed such, and said it had been detected during the FAA vision test which is plausible (that’s how I wound up diagnosed with my version of color blindness, deuteranomalous trichromacy). So… the one eye colorblind, the other not could be due to a genetic mosaic condition, a weirdness with chromosomes, or certain types of injury to the eye. Much more than that I can’t elaborate on as that’s pretty much the limit of my knowledge in that area.

More likely the artist meant they had one of the “color weak” varieties, the ones that end in “-anomalous” (like mine). I don’t perceive green as well as the average person, although I do see green. Protoanomalous trichromacy means the person can perceive red, but not as well as the average person. It is possible to live an entire lifetime with this condition and not know it because it’s not very disruptive in ordinary life. It will show up with an Ishihara test, and if you apply for a pilot’s license or interstate trucking license you might find out then. There are a number of professional artists, including at least one comic book artist (that’s a color-heavy medium) who have one or the other of these conditions so while it might cause issues in some niche areas it doesn’t rule out an artistic career.

Yep, it exists. Unlike red-green coloblindness blue-yellow is equally common among men and women (but still rare). I once worked with a woman who had that version.

True monochromacy does exist, it’s a condition where the cones in the eye are either absent or completely non-functional, not a matter of having “two kinds of colorblindness”. Since cones not only provide color vision but are also responsible for sharp vision their visual impairments involve more than just inability to see color. They are legally blind, daylight can be literally blinding for them as rods don’t function well in bright light, and their eyes sort of jitter as they try to focus with, essentially, peripheral vision. The only even somewhat famous person with this I know of is John Kay of Steppenwolf. This is known as achromotopsia

For bonus points - even more rare is a condition where only the blue cones in the eye are functional. This also results in monochromacy and inability to tell colors apart, but since cones function in daylight these folks are not “day blind” and have better vision than the other variety. But this is even more rare than “normal” achromotopsia.

Finally, Oliver Sachs documented the case of an artist who lost all color perception after a head injury. In that case the eyes were still functioning as always, it was the area of the brain that processed color that was damaged.

No, it’s not hormones. It is possible that female carriers of red-green colorblindness might in some cases have less than optimal perception of color, but unless some thorough testing was done no one would ever know. Most women aren’t tested for colorblindness, that’s much more commonly done for men. We’re probably missing some instances of “partial” colorblindness in women simply because no one is looking for it.

Blue-Yellow is a confusing name for forms of color-blindness where blue frequencies are not perceived correctly or not at all. Other colors become difficult to distinguish such as the difference between yellow and orange, while blue colors are seen as gray. I knew a young woman who had complete Tritanopia, and her favorite colors were yellow and gray.

I have a milder form of colorblindness related to blue colors. I can see blue, although it fades to gray or black easily, but the greatest effect is not being able to detect the blue in blue-green mixes. Something people would normally call teal looks like nothing but green to me. This might have a number of causes related to either or both my blue and green receptors.

Some forms of color-blindness are acquired so there must be people who have different color perception in each of their eyes.

I would interpret the guy’s statement as having an anomalous form of color blindness, such as the most common form of color vision deficiency, deuteranomaly (5%+ of males). They have 3 cone types but the green cone has a peak response at a higher, more reddish, wavelength than is typical, so the overlap of red and green cones is larger. 99% of the time their visual system can compensate and they see color normal, but there will be certain conditions where they have trouble distinguishing hues.

You could have any number of conditions affecting one eye. Most forms of color blindness are genetic and would affect both eyes (unless something weird like the person is a chimera?). Diabetes can affect color vision, but I’m not sure unilaterally. Cataracts are not a color disorder but can add a yellowish cast to one eye and affect perception. Perhaps also some brain abnormality that only affects one ocular column.

red-green types are on the 23rd chromosome or XX/XY and therefore more common in males as females need to get two copies of the gene. Blue color blindness is chromosome 7 and thus equally common for males and females, but also rather rare in general.