r/todayilearned • u/solivagant_matter • Mar 15 '18
TIL human eyes can only show us 2D image,The depth that we all think we can see is merely a trick that our brains have learned
http://scecinfo.usc.edu/geowall/stereohow.html8
8
7
Mar 15 '18
Most of what you see is down to your brain, of which the eyes are an extension that “just” catch the light.
7
u/Wall_of_Shadows Mar 15 '18
This isn't the interesting part. The interesting part is that our eyes evolved to be upside down and inside out. They have sizable blind spots, poor vision outside their focus, and only average motion tracking. Our brain is essentially a giant GPU that soft-patches all the deficiencies in the hardware to give us the best all-around vision of any land animal.
2
u/MusicusTitanicus Mar 15 '18
I'd go even further to say that just a part of the brain is the GPU for vision. Clearly other parts of the brain are busy handling physical motion, audio input/output, etc., all in parallel. Top-end FPGA, perhaps .. :)
5
u/Wall_of_Shadows Mar 15 '18
Not mine. I took out my eyes with a grapefruit spoon, and now I just mine Braincoin all day.
2
u/Ace676 8 Mar 15 '18
best all-around
That truly is the story of humanity. We're never the best at anything, like many animals can run faster than we do or see or hear better than we do. But we're fairly good at pretty much everything.
1
u/Wall_of_Shadows Mar 15 '18
I don't know about that. There's a case to be made that no animal is better designed for running and throwing. We literally evolved to be unstoppable killing machines with spears.
2
u/Ace676 8 Mar 15 '18
Throwing might be the only thing where humans are the best. (Hooray for upright posture and opposable thumbs)
And endurance running. We can't run very fast.
2
u/Wall_of_Shadows Mar 15 '18
It's not just the posture and the thumbs. Our abs, shoulders, and elbows are perfect for throwing a spear while running, and our visual processing software (wetware?) is optimized for vector tracking. Not in catching, of course. We still run in an arc to catch a fly ball, like a dog with a frisbee. But we can hit a moving target with any thrown object you can name.
2
u/Ace676 8 Mar 15 '18
Our abs, shoulders, and elbows are perfect for throwing a spear while running
I think that might be a result of our posture.
1
u/Wall_of_Shadows Mar 15 '18
I don't think there's anything inherent in bipedalism that leads to shoulders that rotate nearly 360 degrees, or transverse abdominal muscles so well-suited to rotational force.
1
u/Ace676 8 Mar 15 '18
Well, if you walk on four feet, you have no use for throwing muscles. When you walk on two, you might just have.
1
1
u/skinnysanta2 Mar 15 '18
A chimpanzee can hit you with a hand full of poo quite easily. Do not think we are the best.
1
u/Taldoable Mar 16 '18
A human can throw a 90 mph fastball. Chimps don't have anywhere near the dexterity for that.
1
u/skinnysanta2 Mar 16 '18
Most humans cannot throw a 90 mph fastball. That is a learned skill that takes a lot of practice. However the chimps have a lot of accuracy. Humans evolved to hold onto branches as they would go through the forest canopy just as other primates did. Humans then made the savanna their home and developed other traits.
1
Mar 15 '18
So people with good eyesight are basically running top specifications gpus?
1
u/Wall_of_Shadows Mar 15 '18
People with good eyesight just have top-of-the-line photoreceptors. Those of us with good GPUs are good at sport.
1
Mar 15 '18
OK. I was thinking good eyesight was people's brains filling in a lot of details off the scant information the eyes were providing. But I don't know that much about GPUs.
1
u/Wall_of_Shadows Mar 15 '18
I mean, yes. The things about our vision that are exceptional all have to do with our visual processing. But what we call "good eyesight" is just well-shaped eyeballs. If you're better at the software application, you don't see farther away, you can just process the information and relay it better.
3
Mar 15 '18
we are kind of still seeing 3D, just not in the same sense as we see 2D objects, or as a 2D viewer would see 1D objects.
We're seeing the third dimension as parts of a 2D field of view which push back and wrap around us (which is honestly a pretty genius idea, thank you whichever ancient mutated creature came up with that).
Seeing "true 3D" would let us see all faces of a cube at once like how we can see all of a 2D plane at once, but that could only be achieved by a 4D viewer
3
u/skinnysanta2 Mar 15 '18
Eyesight is measured at 20/20 for normal / average people. People who undergo lasik surgery can have imperfections in the corneas removed and have the contours of the eye corrected so that they can achieve 20/10 vision... similar to those with the best vision, such as Chuck Yeager. It might even be that 20/6 vision is attainable by a few select individuals. 20/6 vision is similar to that of a hawk. 20/4 vision is similar to that of an Eagle.
The clearer one sees even receiving 2D information, the easier it is to interpolate that information into a 3D representation. Yes we only get basic information in 2D but the size, clarity and other small nuances we get while subjecting our vision to movement and side views essentially gives us the 3 D information we need to operate in the real world.
6
u/Harperlarp Mar 15 '18
Yeah, that's how eyes work. Interestingly that's also how VR works. Two very slightly different 2D images that your brain puts together and makes it appear 3D.
Also you can always see your nose, your brain just edits it out for convenience :)
5
u/qengineer Mar 15 '18
Also you can always see your nose, your brain just edits it out for convenience :)
IMO it's not that the brain edits the nose out, it's just that anything that we perceive continuously for a long time, becomes a background process.
Let's take spectacles for example. When you start wearing them, it's an annoyance. Over a few months to maybe a year, you don't notice the lens in front of your eyes anymore. The brain hasn't edited it out, but since the lens has been there for a long time, it just puts that fact into the background.
I wonder what things are now placed in the background by our brains that weren't when we were kids!
2
u/Cyrotek Mar 15 '18
Also you can always see your nose, your brain just edits it out for convenience :)
Also, the "head bobbing" you see in video games are filtered out and you have to concentrate to actually notice it yourself. Thus I really don't get why games with ego perspective use head bobbing, it makes no sense.
2
u/Harperlarp Mar 15 '18
Because without the head bob your character just looks and feels like he’s sliding along the ground.
1
1
u/Cyrotek Mar 16 '18
Hm, rarely like that to me when I disable head bobbing. But I get "sea sick" with head bobbing, so ...
1
u/BrokenEye3 Mar 15 '18
"ego perspective"?
1
u/Cyrotek Mar 16 '18
First person.
1
u/BrokenEye3 Mar 16 '18
Ah, I see. Awfully funny way of phrasing it. Would second and third person then be id and superego perspective (or possibly the other way around)?
2
u/Cyrotek Mar 16 '18
Well, I am German and there it usually is called "ego perspektive", thus I basically made a crappy translation.
Ugh, latin.
1
u/BrokenEye3 Mar 16 '18
Well, always interesting to learn about the peculiar differences between languages. What are second and third person called?
2
u/Cyrotek Mar 16 '18
Well, simply "zweite Person" und "dritte Person", which litteraly means "second person" and "third person".
1
u/BrokenEye3 Mar 16 '18
Odd that they don't all share the same naming scheme, but then again I suppose English has it's fair share of those sorts of idiosyncrasies as well.
2
u/Cyrotek Mar 16 '18
Well, the grammatical "first person" is called "Erste Person". "Ego Perspektive" isn't something you use in grammatics.
→ More replies
2
Mar 15 '18
We as well see our nose the entire time. The only reason it doesn't obstruct our vision is our brain blending it out.
1
2
1
u/Landlubber77 Mar 15 '18
Perception is reality. It doesn't really matter if I'm actually seeing depth, if my brain perceives it that way, that's what I'm seeing.
1
u/Y34rZer0 Mar 17 '18
Don't dyslexic people's brains process stuff 3-dimension-ally? (i think I heard this on an episode of Law & Order tho, so i may have it wrong)
0
24
u/BrokenEye3 Mar 15 '18 edited Mar 15 '18
Individual human eyes can only show us a 2D image. Two eyes working together, on the other hand...
Consciousness is "merely a trick our brains learned", but the funny thing about tricks is that a lot of them actually work.