A lot of us with ADHD are familiar with the concept of time blindness, but for anyone who isn't: it's a neurological inability to have a consistent sense of the passage of time. If you put me in an empty room, gave me a button and told me to press it when I think it's been 15 minutes, I might press it after..... idk, anywhere between 3 minutes and 2 hours? And if we repeated it the next day the result would probably be wildly different!
But something I've only seen mentioned in one (1) Reddit post, which took some extensive digging to find, is the same effect extending to ALL things measured in numbers. Distance, weight, length, height, amount, space, volume, percentage... For me, small numbers are a bit easier, I could approximate a centimetre probably, but a metre would be much harder and 10 or 100 would likely miss the mark by a lot. Also, anything that can't be easily measured with a ruler or a measuring tape (like weight or volume) is even harder since I don't encounter reference points (like a 1kg hand weight) for those as frequently as I see visual representations of specific lengths.
It's not dyscalculia or anything like that, I'm decent at math (and the OP of the Reddit post was a math major) and I have no other difficulties with numbers, it's just a disconnect in translating real life experiences like sensory input into numbers (and possibly also inconsistent processing of sensory input? Like how the same sound volume is okay one day but hurts my ears the next?), which I think is basically the same thing as what happens with time blindness. For now I've been calling it "measurement blindness" since I've never seen a name for it anywhere, but maybe "quantity blindness" could also work?
I've talked to other people with time blindness to see if they experience this too, but so far none of them have known what I'm talking about. I'd really like to know how many of us are out there and if anyone knows literally anything actually scientific about this very inconvenient phenomenon!
Tl;dr: bc I am wordy:
- It's like time blindness but for all things measured in numbers
- Not dyscalculia or caused by it
- Pretty much never seen it talked about anywhere
- Please tell me if it sounds familiar and/or you know something about it, thank
Oh wait I know this one! So I’ve spent about 5 years doing maker education for a library—like literally developing projects that people can then use to recreate using a cricut or a laser cutter or a 3D printer. Most of these projects involve a digital file. And one thing I learned almost immediately is that numbers mean fuck all nothing to me if I don’t have something physical to relate them to. Especially early on I had to paper piece things together, get them to the size I wanted and then measure them to create the digital file. And even then it wasn’t 100%.
Witness my mess
I’m not sure I ever got this file quite where I wanted it to be.
There is a thing called Nonverbal Learning Disability. It’s not in the DSM yet but it kind of addresses some of what you’re talking about. Folks with NVLD tend to have issues with spatial processing.
From the stuff I’ve read some folks with this are also diagnosed with ADHD. And it kind of makes sense. A lot of people I know with ADHD have issues processing their own bodies in space. We constantly run into door handles, the corner of a table, or the door jam.



