Why do Protan & Deutan look so similar? 

@Venosa They can see blue. The thing is that their brains don't have any other colour to compare it to and so aren't able to process it the usual way.

@venosa7649 To be plain, the world is monochromatic. It is a single color. Whether that color gradient is grayscale or bluescale is kinda beside the point, because to a monochromat, there is no really no difference. What a blue-cone monochromat sees, or a red-cone monochromat is identical once it reaches the brain. However, what we know from cerebral achromats, who have lost their color vision due to brain trauma, is they do in fact relate their new color vision to being GRAY. An interesting read on this subject is Oliver Sacks' Case of the Colorblind Painter. Here is a free pdf: boccignone.di.unimi.it/PMP_2018_files/Oliver%20Sacks_Il%20Pittore_Cieco_ai_colori.pdf

I surmised what occurred at around 0:30, and I'm sorry to say that it was absolutely hilarious, and I'm a horrible person

If you have not done so already, I would love to see you do a vid on Tetrachromacy😎

Thank you very much. Colorblindness is kinda weird, because you can't learn much about it from just having it. My empirical understanding of my own colorblindness was so warped by the language and cultural of the color normals that I didn't understand what I could and couldn't see until I started researching. Puts so much necessary context to my personal experiences.

a person with 1 cone can only see in black and white. because of how the opponency system works at least 2 cones are needed to see any color at all

*SIGH* that kinda defeats the whole purpose of my video doesn't it... obviously I wouldn't know its off just by looking at it. That's kinda the point of the simulations!

making stupid mistakes is how you get engagement on your video, right? *facepalm*

​@@Chromaphobe don't worry, the rest of the video it is fine. So, maybe the beggining will confuse people who have no idea about colourblindness, but they might understand it later down the video.

Those are the basics!

Much obliged! Ask more questions! 😅

Black is just the extreme case, otherwise red and dark brown is common for both deutans and protans. If red almost always look darker than green, then that'd be protan.

@Chromaphobe oh wow thanks for the reply dude I honestly wasn't expecting one from you, I'm only just starting to be interested in learning more about my colourblindness, appreciate your videos 🙌🏼

Then you'll be happy to hear my wife is an engineer too! Confounding factor controlled! I have said before though, that I do believe that color vision does highly influence occupation, and I do expect the incidence of color blindness is higher than what would be otherwise expected from that demographic. So I posit that color vision affects occupation, but does occupation affect jigsawing ability? or are the two just correlated? Hmm... Anyway, they were just silly experiments for a silly video.

I have a feeling I know you from reddit ;-) There are several opponents of the opponent process theory of vision. Importantly, they are not unified and posit very different alternatives and many of them don't so much oppose opponent process theory, but add an extra layer of abstraction, which can be readily omitted in youtube-level explanations of opponent process, just like opponent process can be omitted in many discussion of color vision. Certainly not nearly enough consensus to describe the opponent process theory as "inaccurate". I read that pridmore article a few years ago at the behest of certain redditors. It certainly doesn't represent the state of the art, with only 6 citations in the past decade. It also didn't win me over, seeming to mostly complain about the color names used for unique hues. When the author has to say in the abstract, "this isn't just semantics!" then its probably MOSTLY semantics...

@@Chromaphobe Oh wow, I didn’t your wife was engineer too. I could have sworn I heard you mention she was bad at math, but I must’ve been thinking of someone else. Oops.

@@Chromaphobe I’m not an opponent of Opponent process theory. Where might you know me from reddit?

A person formerly on the colorblind subreddit who was adamant about the theories of Pridmore. We did not see eye to eye on that subject.

My hobby is painting motorcycles in neon/candy colors and I'm disappointed that what I thought was beautiful but he didn't like. I would like to see like him or him like me to enjoy the colors. Thank you!

Get CVsimulator on your phone to let you see like him. There is nothing that will let him see like you. The difference between protan and deutan is mostly academic. You'll see in CVsimulator that they look mostly the same as a first approximation.

I have the application, but I don't know who it represents, deutan or protan. he says when he looks at the color white, it appears a little pink

I opened the simulator on the image and he, looking at it, said that the real image looks like a deutan, but I think that through his eyes it could be the other way around.

Don't worry. Most colourblind folk didn't notice anyway.

Deceptively, protan and deutan are pretty identical. Generally, truist the tests. The only descriptive test I have is whether red text on white looks no different than black. That would indicate protan. If red text is more obvious, than deutan. But just trust the tests.

@@Chromaphobefine red text on white is more confusing to me than fine red text on black, but bold text it's about the same. Also sometimes I can see a pretty strong shade of red that suddenly my brain says is green, and then it can flip back and forth, seems to be the same effect in both eyes. anyways knowing my limitations I never rely on color lol. Thanks for youur very informative youtube channel, great content!

Unfortunately, all tritan glasses are sketchy. I wouldn't recommend them.

@@Chromaphobe Thanks!

Evidence is very strong. Hering first theorised it in 1878 based on the fact that color nornal humans see 4 unique hues, red, yellow, green, blue, that we experience as "pure", in that orange can be explained as yellowy red, but red can't be explained as orangey-purple. There was a lot of pushback since it didn't seem to mesh with the prevailing trichromatic theory at the time (we knew there were 3 cones then). Then in 1920ish Schrödinger proved they could be reconciled (opponent process / tetrachromatic theory with trichromatic theory). In the 50s and 60s, scientists actually found the cells that do the conversion from trichromatic (cone) space to opponent channels, and now we are very confident that all our color vision goes through these opponent cells. There is still a disconnect between the opponent channels and our experience of unique hues, which differ and we don't know why, but there are probably some other neurons deep in our brain that resolve the two. When you shift the L and M cones together, you decrease the dynamic range of the red green channel. When you shift them so they overlap perfectly (the same as removing one), the dynamic range drops to zero. Anyway, all of the early color scientists and philosophers based many of their experiments and opinions by comparing colorblind people to color normals. Colorblindness helped us understand normal color vision. Especially the rare people who are colorblind in only one eye and therefore have a great point of comparison from the same brain.

Magenta would be 100% red and blue with no green I think

Oversimplified? or overcomplicated? When I asked my wife why she thought protan or deutan are different before making this video, she said "because the red and green cones are so close?" and to be honest, that is a decent first answer. I wanted to go in a bit deeper into the opponent channels. After all, how would all of this change if we had blue-green and cyan-red opponent channels from the same cones? Then that simple explanation doesn't work anymore. The full explanation does rest on the virtual yellow cone explanation. It also helps to introduce tetartanopia. I've been really wanting to shoehorn tetartanopia into one of my videos!

That was purple lmao

Just get a Sony monitor.

You do need the cone sensitivities to overlap or there would be no color gradient between them. A rainbow would just be two distinct colors. We also don't know if the red and green cones had reached evolutionary equilibrium by the time civilization started messing everything up, or if they were still diverging from each other, just waiting for the right mutation to push them further apart. The spacing of the cones is definitely very specific depending on the color discrimination needs of the animal and where those lie on the spectrum.

It's estimated that relatively many women and quite a few men have more than 3 cone types. It's not just a "yellow cone", because cone cells don't see colors directly, and also because it's peak can happen all over the spectrum. But experiments about this are difficult as you basically have to destroy the eye to know what kind of cones it contains.

The problem with all of this is of course using colors to describe the cones, which I did only to make the relation to the opponent channel names more plain. Actually, the typical red cone peaks at 560nm which is... almost exactly unique yellow, not red. The "yellow" cone that female tetrachromats have (and its not a very small minority, more than a quarter of women are CVD carriers and therefore weak tetrachromats) are only called yellow because they are cones/opsins that lie between the red and green cones, and yellow is the obvious name - on the surface. Nobody seriously calls them yellow cones though. More correctly, they are M' or L' cones. They do not directly generate the yellow cone signal. They are grouped together with either the M or L cones to contribute to the green or red cone signals, respectively.

@@Schule04 you don't have to destroy the eye! This is what Electroretinography is for!

> Theoretically, it may be possible for some of them to have a misshapen yellow cone which would mean they have what I suppose might be called tetranomaly. This is a misunderstanding on how anomalous trichromacy works. It is not a misshapen cone. It is a shift in the spectrum of either the L- or M- opsin, itself caused by a hybridization of the L- and M-opsins. I've got some videos about that: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-3qFAtbMQqkE.html the wiki page on it is also really good: en.wikipedia.org/wiki/Congenital_red%E2%80%93green_color_blindness anomalous trichromacy is really just any trichromacy that is different from the norm. Anaomalous tetrachromacy can't exist, because there is no 'normal' tetrachromacy.

@@Chromaphobe Thanks for the feedback. Do you have a source for "They are grouped together with either the M or L cones to contribute to the green or red cone signals, respectively."?