The metaphor you want is "color blindness," not "blind spot."

I read this a year or two ago, tucked it in the back of my mind, and continued with life.

When I reread it today, I suddenly realized oh duh, I’ve been banging my head against this on X for months. I’d noticed there was this interpersonal dynamic that kept trying to blow up, where I kept not seeing the significance of phrasings or word choices other people said they found deeply important. I’d been using Typical Mind Fallacy and trying to figure out how to see through their eyes, and it kept not working.

Colour Blindness feels like a close cousin of Typical Mind, but I think there’s a useful difference. Typical Mind Fallacy suggests a solution of practicing empathy and perspective taking. Colour Blindness suggests asking a friend for help to see what you can’t. That can be a much better solution, especially for something you repeatedly fail to grasp.

There’s a frustrating zone where I can predict some input is the kind of thing someone else will be say I’m missing a piece of, but can’t predict which way it will fall. I assume red-green colour blind people notice the cluster of colour they keep making mistakes with.

A problem I have with execution is telling when there’s a real thing I can’t see versus when I’m being mislead. Sometimes the important quality people say you can’t perceive is like N-Rays: confirmed by others even if sometimes you have to squint, but ultimately a kind of placebo or confirmation bias. If multiple people can independantly tell me whether the quality is present or not, I’ve been leaning toward assuming it exists. Show ten people a picture of a red ball and ask if it’s red or green, and you get pretty strong agreement. Still, I’d appreciate better tools for distinguishing real things I don't see from group bias.

I think I don't get it.

My current state is that I plausibly get it enough that I'll understand and find this useful after a week or three of practice (I plan to come back here to report on that unless things are cleared up by further discussion), but right now I feel... confused. I suspect I can't name the true source of my confusion yet, because I don't actually have it in focus yet. (I'm also suddenly all walk-on-eggshells about my usual collection of visual metaphors, apparently.) But if I try to narrow in on an extra bright/sharp confusion place, it's "local" vs. "distributed/omnipresent". 

I think you're trying to say something like "the physiological blind spot corresponds to a single point in the field of vision, so things that are temporarily in that spot become visible as soon as you shift your gaze, and this is the sense in which the blind spot is 'local'".

But like... I think the point of using "blind spot" as a metaphor isn't so much that we sometimes fail to be sensitive to distinctions between things, or that we sometimes fail to see things entirely; it's that we constantly hallucinate things all over the place (globally with respect to external reality, even though locally with respect to the field of vision) and almost never know it. 

Maybe the infrequency with which I talk to other people means I just haven't encountered very often the misuse of the phrase that caused you to write this. (Evidence against that: replacing "blind spot" with "color blind" was really useful for you.) But the way the phrase works in my head is, "Which eyeballs have the blindspot, and which muscles control their gaze?" The point is that while it may only take moving your head to see the thing clearly, it's not always straightforward to figure out what sort of sensory apparatus is affected or how to control its movements, and in the meantime you're constantly making up shit that isn't there and you don't even know which shit you're making up when.

So for me there's a TAP like [notice something fishy is going on with my perception that feels a bit like a combination of not being able to see stuff and making shit up to cover the blindness] --> [engage deliberate perceptual dexterity practices]. Which is a TAP that indeed should not work for color blindness, but I expect I'd be worse at figuring things out if I deleted it and added a color-blindness-appropriate one.

I liked this post. However, I definitely needed you to say more than just a title!

Related: What Universal Human Experiences Are You Missing Without Realizing It? (Slate Star Codex)
 

This piece was reasonably well-appreciated (over 100 points) but I nevertheless think of it as one of my most underrated posts, given my sense of how important/crucial the insight is. For me personally, this is one of the largest epiphanies of the past decade, and I think this is easily among the top three most valuable bits of writing I did in 2022. It's the number one essay I go out of my way to promote to the attention of people who already occasionally read my writing, given its usefulness and its relative obscurity.

If I had the chance to write this over again, I might possibly make it longer and more detailed? I'm torn/conflicted. I don't like that short bits of writing tend to be taken less seriously than longer ones; I would prefer a world where the brief essays packed a punch commensurate with their value rather than their weight. But rather than railing against that dynamic, I think I would just ... flesh this out, so as to give it more felt-sense seriousness.

I might, in such a rewrite, also focus more closely on the key point that blind spots don't live in one spot—they tend to be pervasive, and the way in which they tend to be pervasive is an inability to distinguish between lots of different things. If you're red-green colorblind and don't know it, there are thousands of places where it feels like people are drawing completely meaningless and made-up distinctions that literally don't exist; those two objects are literally the same color, what are you talking about? ... and I see this same sort of blindness crop up in e.g. the writings of people who aren't even aware that they're typical minding, or the behavior of people who don't even know that it's possible to not care about monkey status games, or the update procedures of people who can't tell the difference between a logically sound argument and rhetoric/demagoguery.

I think that increasing the general awareness of what a blind spot feels like, on the inside and what a blind spot looks like, from the outside would go a long way toward improving our ability to do collective rationality. It would improve our ability to wisely defer to one another. It would make it much easier to recognize what's actually going on, in situations where one side thinks the other is making mountains out of molehills, and the other thinks the first is callous or disingenuous or motivated by antipathy. It's a pattern whose shape appears all over the place, and recognizing that "blind spot" was a bad handle for it and "color blindness" was a less bad handle for it has been a huge boost for me, both in navigating my own blindnesses and in more quickly recognizing (and having more productive and constructive reactions to) the blindness of others.

Color blindness is a blind spot in color space.

I have always thought of it like a vehicle blind spot not an ocular blind spot. More related to the structure of the situation than the individual.

They feel like different-but-related thing to me. I would say that colorblindness can be simply that you haven't learned to differentiate some aspects of reality. A blindspot is not just something you can't see but a way in which you're actively hiding from yourself the fact that you can't see it. That's how I use the term "blindspot", which is perhaps downstream of Val / Michael Smith's "Metacognitive Blindspots" presentations (at eg the 2014 alumni reunion iirc, I forget where/when else). "Colorblindness" doesn't cut it for that meaning, so it's not the metaphor I want when I reach for "blindspot".

Having said that, it's a cool metaphor for this different thing, and I can see the temptation to stretch "blindspot" to cover it. Both look kinda similar from the outside if you try to give someone feedback about the thing they're not seeing. I'd say that if someone just has a colorblindness and no blindspot, they would tend to respond more curiously and you'd be able to make some headway starting to point out the dimension and how things vary along it. If someone has a blindspot, trying to talk with them about the thing they're not seeing will feel weird. You'll keep saying things and the conversation will sort of circle around the thing you're trying to point at, or it may feel hard to even put the thing into words while trying to translate it into the other person's frame, or hard to even stay in touch with the thing yourself while talking with the other person.