220 upvotes, 8 direct replies (showing 8)
/u/untempered knows what's up - it's way more ridiculous than you can imagine.
Your optic systems (eyes plus visual processing bits of your brain) are so good at lying to the rest of your brain that you time travel[1] all the time. You can see while your eye is sitting still, but when your eyes move (it's called a saccade) it's like a video feed with a pause button - you get the last image from before the movement, then the camera moves, then once everything is squared away the feed continues. If the new video frame is too far out of sync with the last frame your optic system kinda says "eh... it was probably moving" and *just does it* so the rest of your brain just gets the smooth fill-in-the-blank version.
1: https://www.cell.com/current-biology/fulltext/S0960-9822%2802%2900707-8
This isn't even starting on the part where your eyes are cameras with all of the electronics and such sitting directly between the lens and the sensor... it's incredible that we can "see" at all!
tl;dr: "Seeing" things is incredibly overgenerous. You are blind maybe half the time you're seeing things, and most of your perception of what you see is either faked or old. And because your eyes/brain are such good liars, you have absolutely no idea just how bad things are.
Fun fact: VR developers want to take advantage of this weird eye system to lie to you even more to make games better. If you're walking in a straight line in a headset you're going to run into stuff like walls or furniture. If they take advantage of all those fractions of a second where you're blind to scootch everything a little to the left you would never notice, but you would turn a tiny bit left to compensate and would now be walking in circles.
Comment by JackOfAllStraits at 04/02/2025 at 23:57 UTC
60 upvotes, 1 direct replies
I was so mad when I learned that our optic sensors are backwards. BACKWARDS!!!!
Comment by Kelsouth at 05/02/2025 at 00:40 UTC
13 upvotes, 1 direct replies
Optical illusions work by exploiting the short cuts/filling in the blanks that our brain does. Parallel vertical lines(on a 2d screen)seem longer because our brain is used to things like that being on the ground going off into the distance. Some people's eyes seem to change color if they wear certain color shirts. Their eyes don't change, the brain of the person looking at them gets confused by the contrast and changes what we think their eyes look like.
Comment by gecko090 at 05/02/2025 at 03:36 UTC
8 upvotes, 0 direct replies
This phenomenon is also responsible for the "extra long second" or "stuck second hand" illusion. When we look at a clock with moving arms, ideally one that "clicks" from second to second rather than constant smooth motion, sometimes the second hand will seem like it's taking extra time to tick.
As we look at the clock mid-second, our brain will place the second hand on the next second, creating the illusion of a second that lasts like 1.1 seconds. A kind of visual rounding up.
Comment by florinandrei at 05/02/2025 at 04:01 UTC
10 upvotes, 0 direct replies
It is hypothesized that it goes even beyond that. The brain may run a full-blown reconstruction of the world all the time, with the senses only providing corrections to keep the model on track - little deltas once in a while. This would explain how we do so well when the bandwidth of the senses is so bad.
It would also explain why hallucinations are so convincing and so easy to trigger. It's simply the correction mechanism failing to keep up. The model then goes on and builds a "reality" that's more and more divorced from the actual reality.
Anyway, this is just in the hypothesis stage.
Comment by ULTRA-444 at 05/02/2025 at 00:52 UTC
5 upvotes, 2 direct replies
Wow! That's so awesome! Where do you learn all this?
Comment by schnauzer_0 at 05/02/2025 at 03:28 UTC
7 upvotes, 3 direct replies
I have to ask. How can we drive or fly if we see like this? Why aren't planes and cars crashing all the time?
Comment by Ranra100374 at 05/02/2025 at 06:55 UTC
3 upvotes, 0 direct replies
Your optic systems (eyes plus visual processing bits of your brain) are so good at lying to the rest of your brain that you time travel all the time. You can see while your eye is sitting still, but when your eyes move (it's called a saccade) it's like a video feed with a pause button - you get the last image from before the movement, then the camera moves, then once everything is squared away the feed continues. If the new video frame is too far out of sync with the last frame your optic system kinda says "eh... it was probably moving" and just does it so the rest of your brain just gets the smooth fill-in-the-blank version.
To be fair we'd be seeing a blur anyways so if your brain didn't lie to you, you'd just see a useless blur half the time. It'd be like, okay so you're not blind now but now you just see a useless blur instead of nothing.
Comment by xXGhostrider163Xx at 05/02/2025 at 14:19 UTC
2 upvotes, 0 direct replies
Basically, we see an edited and corrected version of the world, and we have no idea how much of what we perceive is either fake or delayed by fractions of a second.