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"Total color blindness" does not mean "sees only in black and white"
Edit -
The reason I say this is that the phrase "only sees in black & white" in the title could easily be taken literally, making it sound like a simple black-and-white picture. While it's the most common and helpful analogy, colorblindness is more nuanced than that. I suggest a slight change in the title to offer more clarity:
~Rant about people's reactions in this comment thread~
spoiler
This concept is clearly difficult to convey, I get that. However, I am disappointed that some reactions focused on criticism of my articulation rather than seeking clarification or offering alternative explanations. I tried an analogy using NULL to illustrate the conceptual difference, but that was also met with criticism focused on its imperfections rather than the concept I was trying to convey.I have a range of close, personal experiences with colorblind people, and the conversation of colorblindness has come up frequently. I have also confirmed my understanding of the deeper nuances with optometrists and a neuro-ophthalmologist. My intention was simply to share my information, which I believed was the purpose of this community. It is disheartening to feel that my attempts to communicate were met with such negativity.
I have no idea what you're saying, but their receptors work in 1D instead of 3D color space. Dimensionality of black-white/brightness is 1D so the analogy is correct, they see in the same number of dimensions as black-white vision. We do not know how their brain actually interprets though.
Actually, you've pretty much nailed what I've been trying to say.
That's a good way of rephrasing my point. Calling it "black and white" is an analogy and not explicitly what they see. While we don't know how the brain interprets vision without comes from our perspective ("is my blue your blue?"), it's not "black and white" in the way we know it.
The title just states it as if they explicitly see only "black and white" and I was just trying to point out the difference. It spreads bad information phrased like that.
I read through the article and followed the links and it still isn't clear to me exactly how much, if any color they can see.
Achromatopsia, also known as rod monochromacy, is a medical syndrome that exhibits symptoms relating to five conditions, most notably monochromacy.
Well, it states "total color blindness" so, effectively none.
My point is that when you have "total color blindness" it simply means you cannot effectively discern the difference of of color. That does not mean "black and white."
For example, everyone has a blind spot in their eye where the optic nerve passes through the retina. This area has no photoreceptor cells, so there is a spot in each eye that cannot see. When you look through one eye and close the other, do you see a black void spot? Is it a blank white area? No. It's just... nothing.
Are you thinking of cerebral achromatopsia, rather than congenital achromatopsia? As far as I can tell, rod monochromats really do see in grayscale.
No. The article states "total absence of working cones in their eye retinas, leaving them with only rods".
I'm trying to say that not being able to see color does not mean black and white or grayscale, it means the brain does not decipher color hue.
My example of the blind spot was to outline that a lack of receptors does not mean black, white, grey, whatever. It means a lack of signals to the brain to process anything. In the case of lacking cones, it means an inability to process color. When it's described as "grayscale" that's to help people understand a concept that is difficult for some people to grasp.
Think of it this way. Black is like 0, White is like 1, and Grayscale would be a float (decimal) between 0 and 1, while Colorblind is like
NULL.Null would be completely blind, no visual data at all. Monochromacy is receiving a single visual channel instead of the more common r,g,b. The original Nosferatu had more colour than that and very few people would argue that's not a black and white movie.
Then what is 0 and 1 when you interpret my example like this? I think you missed the point of my example.
The whole point is to say that "no color" does not mean black and white. It just means no color data. Similar to how a person born completely blind does not see all black, they just don't see anything at all. They don't receive any visual data and their brain does not process color, light intensity, or any optic information at all.
0 to 1 is monochromacy, a single visual channel, eg only rods and no cones. I thought that was fairly clear. Full colour vision would be closer to 0,0,0 to 1,1,1 (plus low-light rods). Null would be no visual channels at all, ie completely blind. I didn't miss the point of your example, it's just a very bad analogy.
Here's a quick article I found which demonstrates how individual channels are monochromatic and you only get full colour by combining channels, digital image formats were designed for human eyes so this is much more analogous to human vision. With no channels you get nothing at all.
I don't need an article to describe how colors are reproduced through RGB, not only because I already am familiar with it but because it is irrelevant to the discussion.
The problem is that you're trying to relate things that are entirely incompatible. You cannot describe the concept of an entire lack of any experience with color by using colors. That's the exact issue I am trying to point out. The idea of "black and white" or "grayscale" simply requires having experience with color, so that does not apply.
It seems you came here just to piss on my analogy, rather than trying to help and have a discussion.
Hey man, don't bring IEEE 754 into this unless you want to discuss how negative zero, infinity, NaN, and subnormals relate to the qualia of color perception.
Look, it was not a perfect analogy. There's no need to be nitpicky and only focus on the fact the analogy is not perfect. I was grasping at straws to try to convey a difficult concept while I felt people were attacking me.