
Scientists have found a woman whose eyes have a new type of color receptor - wolfgke
http://www.sciencealert.com/scientists-have-found-a-woman-whose-eyes-have-a-whole-new-type-of-colour-receptor
======
vanattab
I was just reading the Wikipedia article on Tetrachromacy and saw this
interesting fact.

"Humans cannot see ultraviolet light directly because the lens of the eye
blocks most light in the wavelength range of 300–400 nm; shorter wavelengths
are blocked by the cornea.[27] The photoreceptor cells of the retina are
sensitive to near ultraviolet light and people lacking a lens (a condition
known as aphakia) see near ultraviolet light (down to 300 nm) as whitish blue,
or for some wavelengths, whitish violet, probably because all three types of
cones are roughly equally sensitive to ultraviolet light, but blue cones a bit
more."

[https://en.wikipedia.org/wiki/Tetrachromacy](https://en.wikipedia.org/wiki/Tetrachromacy)

~~~
hatsunearu
Hmm, I see those "blacklight" CFL ultraviolet lamps as violet-white. I see the
sameish color on ultraviolet lasers. Am I the only one who sees it that way?
Can anyone describe how they perceive those lamps?

Communicating color is extremely difficult!

~~~
jhayward
> Communicating color is extremely difficult!

Odd personal anecdote: In first grade art class the teacher held up a piece of
art paper and said "This is red". Being the curious student I was, I raised my
hand and asked "how do you know?" I was looking for something that would
answer both "how do you know I perceive red the same way you do" and also
"what defines it to be red". Something about wavelengths and color spectrum
etc. would have been a great answer.

I was sent to the principal's office as a troublemaker. Never did like art
class after that.

------
Roboprog
Did anybody happen to see anything in the article about what wavelength the
extra cone type was actually (most) sensitive to???

The article hyped the "millions of colors" aspect, but nothing about whether
it was deeper reds, higher blues, or just more precise yellows (or whatever).

~~~
chriskanan
cDa29 is a cone that is a deuteranomaly, which is a kind of altered
sensitivity to green light. So, presumably she has better discrimination of
yellows/greens/reds, and not blues.

See this 2010 paper for details on this person:
[http://vision.psychol.cam.ac.uk/jdmollon/papers/JordanDeebBo...](http://vision.psychol.cam.ac.uk/jdmollon/papers/JordanDeebBostenMollonOnTetrachromacy.pdf)

~~~
Roboprog
Ah, thanks. So further improved primate detection of ripe fruit, then.

------
vanderZwan
There's also the story of Concetta Antico, who is also supposedly a
tetrachromat _and_ a painter.She claims to add hues to her paintings that she
sees but we do not. Researchers are looking into her abilities.

[https://en.wikipedia.org/wiki/Concetta_Antico](https://en.wikipedia.org/wiki/Concetta_Antico)

[http://www.huffingtonpost.com/maureen-seaberg/worlds-
first-t...](http://www.huffingtonpost.com/maureen-seaberg/worlds-first-
tetrachromat_b_5832242.html)

[https://concettaantico.com/oil-paintings/](https://concettaantico.com/oil-
paintings/)

(watching her paintings through what is likely an LCD screen that isn't even
wide gamut is a bit ironic, of course)

------
ryao
Why would only women be capable of tetrachromacy?

I am a man, but if the test is made public, I would be interested in testing
myself. I am not color blind according to color blindness tests, but there
have been instances where I disagreed on the color something was with others
and while I could consistently use the name that they used for it, I felt it
really ought to have been named something else. One involves "green" status
LEDs on electronics, which seem more in common with yellow than green to me.
They look different from yellow, but they seem closer to yellow than green to
me and for lack of a better word, I would rather call them yellow. If I could
use a different name for the color, mapping it to green when interacting with
others would seem less weird. Another involved the paint of a house when I was
young, whose color seemed to poorly resemble what my parents said it was when
it was dark. The house has since been repainted. Having three primary colors
never made much sense to me either, but that could just be my own ignorance.

Anyway, I am sure that there are many more variations in human vision than we
realize. The dress incident brought that to light:

[https://en.m.wikipedia.org/wiki/The_dress_(viral_phenomenon)](https://en.m.wikipedia.org/wiki/The_dress_\(viral_phenomenon\))

It would be nice to have ways of categorizing them.

~~~
TeMPOraL
> _Having three primary colors never made much sense to me either, but that
> could just be my own ignorance._

Tree primary colors thing seems to be mostly ignorance of the educators
teaching that stuff to children. There are no absolute "primary colors" \-
basically, you can pick any colors at random and use them as a base for linear
combinations; the set of colors you can express as such linear combinations
form a color space defined by those base colors you picked. Red, green and
yellow are a common historical picks, RGB is more common now because that's
what is put on the computer screen, but CMY form a color space too.

C.f.:
[https://en.wikipedia.org/wiki/Primary_color#/media/File:CIE1...](https://en.wikipedia.org/wiki/Primary_color#/media/File:CIE1931xy_sRGB.svg)
\- the triangle inside is the color (sub)space of RGB overlayed on CIE 1931
color space
([https://en.wikipedia.org/wiki/CIE_1931_color_space](https://en.wikipedia.org/wiki/CIE_1931_color_space)).

Source: I educated myself when I got asked by a local drunk to resolve a bet
between him and (presumably) another local drunk while I was shopping in a
local grocery store. Those two got into a bet over whether RGB or RGY are
primary colors.

~~~
derekp7
I always understood it as RGB being additive -- each color directly stimulates
a given color cone in the eye. Whereas process colors (CMYK) are subtractive,
because they are a tint. White light hits the paper, but each color (Cyan,
Magenta, or Yellow) takes out a certain RGB color leaving the remaining two
colors to reflect off the paper. For example, Cyan is a filter for Red,
leaving Green and Blue to reflect.

~~~
TeMPOraL
I'd say it's a property of the medium, not of the colors. Computer screens
blend additively because you emit a mix of light waves; pigments blend
substractively because they are filtering out wavelengths from incoming white
light. Color spaces and "primary colors" are orthogonal to that.

------
schoen
I thought the discovery of individual tetrachromats had been reported several
times in recent years. This article seems to suggest that women who were
anatomically capable of tetrachromatic vision were found before, but that none
of them were successfully confirmed to be tetrachromats in practice until this
new study. Is this really the case?

~~~
dekhn
yes.
[http://www.digitaljournal.com/article/326976](http://www.digitaljournal.com/article/326976)
[http://jov.arvojournals.org/article.aspx?articleid=2191517](http://jov.arvojournals.org/article.aspx?articleid=2191517)

~~~
schoen
Hmmm, that shows that this research finding was published in 2010, which might
be the timeframe I was thinking of. I first thought from the link that this
article was newly published.

~~~
dekhn
yeah, me too.

------
tvon
Reminds me of this bit from BSG (a conversation between two "artificial"
humans):

    
    
        Cavil: In all your travels, have you ever seen a star supernova?
    
        Ellen: No.
    
        Cavil: No. Well, I have. I saw a star explode and send out the building blocks
        of the universe, other stars, other planets, and eventually other life, a
        supernova, creation itself. I was there. I wanted to see it, and be part of the
        moment. And you know how I perceived one of the most glorious events in the
        universe? With these ridiculous gelatinous orbs in my skull. With eyes designed
        to perceive only a tiny fraction of the EM spectrum, with ears designed only to
        hear vibrations in the air.
    
        Ellen: The five of us designed you to be as human as possible.
    
        Cavil: I don’t want to be human. I want to see gamma rays, I want to hear
        X-rays, and I want to smell dark matter. Do you see the absurdity of what I am?
        I can’t even express these things properly, because I have to — I have to
        conceptualize complex ideas in this stupid, limiting spoken language, but I
        know I want to reach out with something other than these prehensile paws, and
        feel the solar wind of a supernova flowing over me. I’m a machine, and I can
        know much more, I could experience so much more, but I’m trapped in this absurd
        body. And why? Because my five creators thought that God wanted it that way.

------
saganus
It's very exciting for me to dream of a future where we manage to tap into the
visual cortex and maybe then we'll be able to see as if we had 4 or maybe more
cones.

I really hope this result is verified and confirmed. It's very interesting to
think what would it mean to see like this. Could we liken it to jumping from 8
bit color to 32 bit color for example?

~~~
schoen
Nope, the trichromatic vision is the reason we use color spaces like RGB -- it
means that combinations of three colors can produce nearly all of the
subjective hues that we experience. The idea of "three primary colors" comes
from trichromatic vision; there's nothing about physics that implies that
there should only be three primary colors, and machines can be built to
distinguish an unlimited range of hue combinations that are not regarded as
built up from _any_ finite number of primary colors, whereas human vision
simply can't make these distinctions.

Tetrachromatic vision means a four-dimensional color space which will have to
use four, not three, primary colors in order to represent all subjective hues
through combinations. So you would need to add another channel on top of RGB.

The bit depth in a color space is effectively about how many different
intensities of each primary color can be distinguished (although you can have
a system that measures or distinguishes colors in terms of other features
instead). So if you have a greater color depth, you can make more fine-grained
distinctions about the intensive of the primary colors, but having a new
primary color (that reaches otherwise-unrepresentable colors!) is something
else entirely.

~~~
gm-conspiracy
What about CMYK for tetrachromatic?

~~~
scardine
I think the primary difference between CMYK and RGB is that CMYK is a
subtractive color space, while RGB is cumulative (I don't know if these are
the correct terms in English). The first is used for reflective surfaces,
while the other is used for light sources.

On reflexive surfaces, you make colors by subtracting wave lengths (the paint
has pigments that absorb specific wavelengths). On light sources, like our
computer screens, we make color by combining primary wavelengths.

------
amai
See also [https://theneurosphere.com/2015/12/17/the-mystery-of-
tetrach...](https://theneurosphere.com/2015/12/17/the-mystery-of-
tetrachromacy-if-12-of-women-have-four-cone-types-in-their-eyes-why-do-so-few-
of-them-actually-see-more-colours/)

------
amai
This is not news. This article is based on another article from 2012
([http://discovermagazine.com/2012/jul-aug/06-humans-with-
supe...](http://discovermagazine.com/2012/jul-aug/06-humans-with-super-human-
vision)).

~~~
amai
And actually the whole story is based on a paper from 2010:
[http://vision.psychol.cam.ac.uk/jdmollon/papers/JordanDeebBo...](http://vision.psychol.cam.ac.uk/jdmollon/papers/JordanDeebBostenMollonOnTetrachromacy.pdf)

