Blind and Visually Impaired Community
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What's something you didn't know about sighted people until later in life? (self.Blind)
submitted by Mokohi
Just a fun question I was curious about. I was born with my visual impairment and so, there are things I didn't immediately realize about sighted people and sighted life. Here's one of mine to start off:
I didn't know you could see inside windows until high school. I thought you could only see out, but not in.
I didn't know you could see inside windows until high school. I thought you could only see out, but not in.
TK_Sleepytime 19 points 4y ago
Here's something I still don't understand as someone who only has one eye. In biology books they would show a picture of a sunflower field to explain depth perception and the caption would say something like "To a person without depth perception, this field would appear flat like a picture." But like, it IS a picture????? I'm 40 now and still mad about my freshman biology book. When I have to explain my lack of depth perception to others I just say, "Please don't throw things to me, I can't catch them." But I really have no idea what depth perception is supposed to look like.
PistachioCaramel 19 points 4y ago
>But I really have no idea what depth perception is supposed to look like.
It's really quite a subtle effect.
If I close one eye, it's not as if everything all of the sudden just changes, and I'm like "whoa, I can't judge depth any more". If I had to venture a guess, I'd say 90% of my estimation of depth is based on contextual clues and prior knowledge about the world around me - not on stereo-vision:
* Occlusion: Things in front of other things occlude them
* Parallax: When I move, foreground elements shift in relation to background elements more or less, depending on how far way they are from each other
* Sizes of well-known objects: If something appears tiny, given its usual size, it's far away, and vice versa
Depth perception helps in visually **ambiguous** situations - elements with the same color and texture occluding each other for example. So, a single tree branch with leaves in front of other trees or a forest disappears into a green, chaotic mess if I close one eye.
With both eyes open, it helps to separate it from the background: I can pretty clearly recognize the outline of the branch as something that is closer to me, and it feels more dominant and more "clear" in my field of vision than the greenery behind it.
With stereo-vision, we basically get a double image for everything that isn't in the plane of focus. That double image is not something you'd ever really notice, unless you pay attention to it, but it's there. And the further away (front or back) something is from the plane you're currently focussing on, there more extreme the shift gets between the two images.
It's really quite a subtle effect.
If I close one eye, it's not as if everything all of the sudden just changes, and I'm like "whoa, I can't judge depth any more". If I had to venture a guess, I'd say 90% of my estimation of depth is based on contextual clues and prior knowledge about the world around me - not on stereo-vision:
* Occlusion: Things in front of other things occlude them
* Parallax: When I move, foreground elements shift in relation to background elements more or less, depending on how far way they are from each other
* Sizes of well-known objects: If something appears tiny, given its usual size, it's far away, and vice versa
Depth perception helps in visually **ambiguous** situations - elements with the same color and texture occluding each other for example. So, a single tree branch with leaves in front of other trees or a forest disappears into a green, chaotic mess if I close one eye.
With both eyes open, it helps to separate it from the background: I can pretty clearly recognize the outline of the branch as something that is closer to me, and it feels more dominant and more "clear" in my field of vision than the greenery behind it.
With stereo-vision, we basically get a double image for everything that isn't in the plane of focus. That double image is not something you'd ever really notice, unless you pay attention to it, but it's there. And the further away (front or back) something is from the plane you're currently focussing on, there more extreme the shift gets between the two images.
TK_Sleepytime 8 points 4y ago
THANK YOU. This is amazing. You're the first person to actually explain it to me. If I had enough coin for gold, you'd get some. Have a silver. :)
PistachioCaramel 7 points 4y ago
My first gilded comment - thank you :)
I'm glad it actually helped - I was afraid that it was all a bit abstract, and I was explaining more the *how* it works than what it *feels* like (which is quite difficult to convey).
I was thinking of another comparison (which I didn't put in the first comment, because it was already getting long): The way depth perception *feels* to me is a bit like the effect of $1 in computer graphics. AO is basically an advanced lighting/shading method in 3D rendering that also takes into account that objects can shadow themselves, depending on their shape. So it's not just "directional light hits object, casts shadow on another object".
If you look at the very first image in that post, you'll notice that there is no actual directional light source casting any shadows (that image consists *only* of an AO layer). All the shadows that are in there are the effect of that soft, diffuse ambient light not quite getting into all the nooks and crannies. Such an AO layer then would get combined with regular lighting, $1.
Unless seen on its own, in a greyscale clay render like that, it's also quite a subtle effect. But it really accentuates the shape and plasticity of objects. That first image with the AO-only layer is like pure shape-ness, if you will. It puts emphasis on the edges of things, and helps separate them from their background.
So that's sort of what depth perception feels like to me. At least that's the closest visual approximation I can think of, that can be shown with 2D images. Unlike the picture of the sunflower field in your biology book :) I still don't quite understand how that could possibly work as an explantion.
I'm glad it actually helped - I was afraid that it was all a bit abstract, and I was explaining more the *how* it works than what it *feels* like (which is quite difficult to convey).
I was thinking of another comparison (which I didn't put in the first comment, because it was already getting long): The way depth perception *feels* to me is a bit like the effect of $1 in computer graphics. AO is basically an advanced lighting/shading method in 3D rendering that also takes into account that objects can shadow themselves, depending on their shape. So it's not just "directional light hits object, casts shadow on another object".
If you look at the very first image in that post, you'll notice that there is no actual directional light source casting any shadows (that image consists *only* of an AO layer). All the shadows that are in there are the effect of that soft, diffuse ambient light not quite getting into all the nooks and crannies. Such an AO layer then would get combined with regular lighting, $1.
Unless seen on its own, in a greyscale clay render like that, it's also quite a subtle effect. But it really accentuates the shape and plasticity of objects. That first image with the AO-only layer is like pure shape-ness, if you will. It puts emphasis on the edges of things, and helps separate them from their background.
So that's sort of what depth perception feels like to me. At least that's the closest visual approximation I can think of, that can be shown with 2D images. Unlike the picture of the sunflower field in your biology book :) I still don't quite understand how that could possibly work as an explantion.
TK_Sleepytime 9 points 4y ago
Thanks so much for taking the time to give me all of this and explaining in a kind manner. You have no idea how ridiculously happy it has made me to finally feel like I get it to some degree. And I'm glad I'm not the only one who felt the biology book's explanation was lacking. I asked about it in class and the teacher told me, it's saying that to you the world looks flat like a picture. Um... No, it doesn't. :/ I would have a hell of a time walking through space if that were the case haha.
eversincenewyork 2 points 4y ago
as someone who also only has one eye this is so helpful! thank you!!
nueoritic-parents 2 points 4y ago
r/nocontext
preiman790 4 points 4y ago
What they’re trying to say, is that the actual field would appear flat like that picture, which isn’t exactly right, but is probably about as close as you’re going to get when somebody without a visual impairment is trying to explain what somebody with that visual impairment experiences, to other people without visual impairments. That sentence made me dizzy
TK_Sleepytime 2 points 4y ago
haha. Yeah, I get what they were trying to say about the field and it's wrong. That's why it annoyed me so much. It explained nothing. I've never thought of things as looking flat. Appreciate the understanding of the impossibility of explanation though :)
Mokohi [OP] 3 points 4y ago
Can you actually see depth in pictures? You just threw me for a loop too, haha. I had no idea that's a thing if so. I also lack any depth perception.
Tower3lights 5 points 4y ago
sighted person, no you cannot see depth in pictures. The book is trying to say that the field would look like the picture in the book for a one eyed person, but a 2 eyed person it would look different in real life because of their focal point.
Mokohi [OP] 1 points 4y ago
Oh, okay! That makes sense.
preiman790 4 points 4y ago
You really can’t, though there are tricks that a photographer can use to give the illusion of depth
Mysterybanjo 16 points 4y ago
I didn’t know people could see stars until I was about 10 and my uncle took me to an observatory, thought you just saw them in pictures
LittleTay 9 points 4y ago
I am so glad I'm not l am not the only one. I couldn't tell you if I ever saw stars in person until about 5 or 6 years ago when a friend surprised me by taking me to a beach at night where there was no city light. I still never could see the same amount of stars that are in pictures. Just the big glowy ones. I hope one day I can see them as well as pictures do.
commandersaki 6 points 4y ago
Turns out a lot of city children miss out due to light pollution. I’m glad I grew up in a bit of a sparse city where starry skies were normal!
Mokohi [OP] 5 points 4y ago
Oh, that is definitely true! I can't really see stars either unless they are very bright or it's a very clear night.
ravenshadow2013 8 points 4y ago
I thought all birds were were all dark shades of gray, until a few years ago when a blue jay landed near enough for me to see the color
CloudyBeep 3 points 4y ago
Many birds aren't grey. They may even have color words in their names.
ravenshadow2013 4 points 4y ago
yeah but at a distance they all still look gray to me
cae_jones 2 points 4y ago
Blue feathers are actually kinda weird from a physics perspective, and work kinda like the sky, water, blue eyes, etc. None of these are actually blue the way that grass is green or blood is red. Normally, the color of something is just what light bounces off of it, or gets reemitted. With blue feathers, eyes, etc, they're more or less transparent, but scatter light as it passes through them. It scatters from the shortest wavelengths to the highest, which usually means it scatters the blue light and most of that is what reaches us.
This explains quite a few little querks, like blue birds looking grey sometimes, or the crazy things some of the blue eyes in my family have done (is it green? Is it a cat? Is it the color of your shirt?), and sunsets (at the angle of a sunrise or sunset, all of the blue has been scattered, and you start seeing all the other colors as they get scattered). If you crush a blue feather, you get whitish powder.
Fun fact: sunsets on Mars are blue, because the atmosphere is thinner.
This explains quite a few little querks, like blue birds looking grey sometimes, or the crazy things some of the blue eyes in my family have done (is it green? Is it a cat? Is it the color of your shirt?), and sunsets (at the angle of a sunrise or sunset, all of the blue has been scattered, and you start seeing all the other colors as they get scattered). If you crush a blue feather, you get whitish powder.
Fun fact: sunsets on Mars are blue, because the atmosphere is thinner.
baistei 8 points 4y ago
I still feel this way about windows and I'm 31. I'm always forgetting that people can see in! Same with cars. I didn't realize people could see other people driving while driving. I'm colorblind too and just recently learned that the walk and don't walk signals are not actually red and green at all!
preiman790 3 points 4y ago
they can be though, walk can be green or white depending on where you are and don’t walk is always red.
aussiecrunt 2 points 4y ago
What colours are they?
mobiledakeo 2 points 4y ago
The don’t walk hand symbol is a red kind of dark orange sometimes and the walk symbol is white and is a man walking
baistei 2 points 4y ago
Apparently they are white and orange.
CosmicBunny97 7 points 4y ago
I'm completely blind in my left eye but have sight in my right. I didn't know that people who can see out of both their eyes can't see their nose until my boyfriend told me!
WolfTitan99 3 points 4y ago
People with both eyes CAN see their nose, just the tip of it anyway. We’re just really good at ignoring it until its a blind spot because its always there. The nose is right on the edge of our vision.
mdds2 1 points 4y ago
Do you see your nose?
CosmicBunny97 1 points 4y ago
The side of it, yeah.
mdds2 2 points 4y ago
I covered one eye and after I tried really hard not to think I realized that there is a dark spot in the bottom corner of my vision which would be my nose. That’s really interesting, I never would have thought about it if I hadn’t stumbled across this thread.
Thanks :)
Thanks :)
cae_jones 4 points 4y ago
How much they rely on vision. I mostly just thought it was a matter of sighted people seeing things that I couldn't, and therefore being able to read / drive / find tiny things / swat mosquitoes / etc Then i heard my sister complain that she couldn't buckle her seatbelt because it was too dark, and was all like "huh?".
I was always kinda unclear on how far people can see, and in how much detail. It's still not entirely clear. The ability to see bugs smaller than a grain of rice without a magnifying glass kinda blows any sense of scale into question.
But then you get to cleaning counters / dishes / etc, and it turns out that a lot of the stuff I can feel is apparently invisible. This results in neatfreaks having kitchen counters that feel like someone poured a mix of sand and glue all over the place and decided to pretend it never happened.
I was always kinda unclear on how far people can see, and in how much detail. It's still not entirely clear. The ability to see bugs smaller than a grain of rice without a magnifying glass kinda blows any sense of scale into question.
But then you get to cleaning counters / dishes / etc, and it turns out that a lot of the stuff I can feel is apparently invisible. This results in neatfreaks having kitchen counters that feel like someone poured a mix of sand and glue all over the place and decided to pretend it never happened.
samarositz 2 points 3y ago
Well, thank you all. I've never understood distance and level of detail they can see either. One time I was talking with a person who was born nearly deaf and she told me she couldn't understand that person talking across the room because they were too far away. It caused me to understand that she didn't understand distance and sound in exactly the same way I didn't understand distance and sight. Hope I explained that well enough.
noaimpara 2 points 4y ago
Depth perception still bagfles me
__OliviaGarden__ 1 points 4y ago
Well as a sighted person, I hope you know that it confuses the hell out of me too
[deleted] 2 points 4y ago
[deleted]
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