What Do Blind People Actually See?

http://nautil.us/blog/what-do-blind-people-actually-see

by dnetesn • 12 years ago

304 118 12 years ago

jareds4• 12 years ago

As someone who has been blind since birth this is accurate. I know that people who go blind later in life continue to dream in color since they have the memory of color to reference while I do not. I wonder if someone who goes blind later in life experiences things differently, possibly by automatically filling in what they assume they would see based on what they know of there surroundings from there other sences.

mey• 12 years ago

Have you considered a haptic device like the one in the article?

jareds4• 12 years ago

No. I've found that a GPS on a smart phone works fairly well for me if it's an area I am generally familiar with.

hentrep2• 12 years ago

I've always wondered how someone born blind is able to wrap their mind around the concept of color. It appears you've done so -- how would you describe color?

Chinjut• 12 years ago

Why should the concept of color be harder to wrap one's mind around or describe than the concept of sight itself? Or, considering any animal with any kind of sensory receptors other than those you yourself have, wrapping your mind around or describing the concept of the data produced by such receptors? [A bat's echolocatory sense, say, or magnetoception...]

["Oh, it's easy to understand the PHYSICS and BIOLOGY of color, but can the blind really comprehend the EXPERIENCE of color?", some might say. Alright, fine, shades of "What Mary Didn't Know", but I'm not keen to get into that.]

jareds4• 12 years ago

I don’t have any meaningful concept of color. I do have some light perception so assume that white is what I see if you shine a light in my eye, black is what I see when all the lights are turned off and gray is the middle ground when there are some lights turned on but not enough for the light to actually be painful. Intellectually I realize there are other colors but the only way I can explain them is in reference to objects. Grass is green, the ocean is blue, etc. I realize that this is meaningless since I don’t have a frame of reference to compare the ocean to grass from a visual perspective.

marcosscriven• 12 years ago

This reminds me of musicians, particularly those with perfect pitch, who talk of 'colours' of keys. While it's not a direct analogy, perhaps one way to think of colour, if you've never seen it before, is to think of different wavelengths of sounds being a bit like different wavelengths of light.

furyofantares• 12 years ago

I imagine a blind person can study light just as well as anyone else, and can learn about the eye and can understand that sighted people are able to detect both wavelength and intensity differences. Just like a deaf person could learn about pressure waves in the air and how they can be detected by functional ears.

But it's probably difficult or impossible to understand what the perception is like, and how rich it is, except by analogy when thinking about how they'd try to describe the senses the do have to someone that doesn't have them.

Our understanding of echolocation in bats or the magnetic field in birds is probably similar. We understand what they detect and how they detect it. But I don't think we have any understanding of what it's like to experience that perception.

gliese13372• 12 years ago

I am not blind, but I do occasionally get migraines with visual auras, as do my wife & mother. Exactly once in my life that I recall, I had a migraine that caused total perceptual blindness (oddly, this has also happened exactly once to my wife, before we knew each other). It's extremely odd- one's visual field (at least in our cases) steadily contracts, until there's just nothing left. It's not an annulus of darkness closing in, it's juts nothing- the field you can see is smaller, and there's still nothing outside of it, just like there always isn't. Like what the back of your head looks like, as the article says.

In the end, you literally see Nothing. It's truly bizarre[1]. It's not an experience I particularly want to repeat, but I'm kinda glad it happened just once, for the empathy value. It's not really something that can be effectively described if you haven't (not) seen it yourself; even now, I have trouble re-imagining the experience, 'cause my memory wants to fill in blackness or grayness or whatever. But at least in theory I now know exactly what the Nothing from _The Neverending Story_ (doesn't) look(s) like. :)

[1] What makes it even more bizarre is that migraine blindness is a strictly neurological effect- there's no damage to your eyes or optic nerves- which means you can get temporary blindsight. In my wife's case, this meant she managed to walk a couple blocks home from a friend's house, crossing suburban streets and so forth, totally normally, while all the while convinced that she was completely blind. Which, as far as conscious perception goes, was the truth!

sillysaurus32• 12 years ago

It's extremely odd- one's visual field (at least in our cases) steadily contracts, until there's just nothing left. It's not an annulus of darkness closing in, it's juts nothing- the field you can see is smaller, and there's still nothing outside of it, just like there always isn't.

This is the first time I've heard of anyone else experiencing this phenomenon besides myself. Have there ever been any long-term effects on you?

Mine is slightly different. I don't have migranes, for one. Also, in addition to experiencing exactly what you described (minus the migrane), sometimes I experience the inverse: I can no longer see whatever I look at, but I retain peripheral vision. For example, if I were to look at the "o" in the word "for," I wouldn't be able to see the entire word. I could still read, with difficulty, until the effect became so strong that reading was impossible. (I still had peripheral vision, sort of, but eventually paragraphs became unseeable rather than individual words.)

Whenever any of these things occurred, I was completely normal again within two hours. It was bizarre, and it's mystified myself and two eye doctors. It's only happened less than a dozen times, but it's been happening since I was very young, and my most recent was less than a year ago.

The "blindness" was exactly as you describe: not a blackness, but a nothingness.

Do you happen to have any more info about the condition? It's very elusive.

titter2• 12 years ago

I also have had many migraines with visual aura, and have exactly one similar experience of perceptual blindness.

kazinator• 12 years ago

I've had a few auras, and my experience was different. There was an ever increasing spot of vision missing, which came to engulf half my vision, but of course I'm aware that the missing part is cutting into my field of vision; I could still map the places in the field of vision where I should see external objects, and imagine something superimposed there. I would say that it was similar to (but eventually larger than) the natural blind spot that occurs where the optic nerve meets the retina. There is no specific color there (it is not black), but we know that an object which should be seen has disappeared because of that spot, and we can imagine that it ought to be there.

I'd like to add that I had a recent recurrence of an aura, after some twenty years! It did not precipitate in a headache, and it was the type with a zig-zag edge surrounding the blind spot: an edge of shimmering color. After it came and went, I prepared myself for a headache, but it never happened.

guard-of-terra• 12 years ago

"one's visual field steadily contracts"

This sounds like tunnel vision. I get that when I'm not feeling well (for example, some kind of gut disturbance).

GabrielF00• 12 years ago

I've been blind in my left eye since birth and kids often asked me what I saw, assuming that it was just blackness. In my case if you shine a flashlight in my left eye at the right angle I can see a flash of color, but otherwise there's just no perception at all.

It's probably worth clarifying what we mean by blind. The article and the parent comment are talking about having no light perception at all. However, many (I think most) people who are considered legally blind do have at least some light perception. The legal standard in the US is vision that can be corrected to at best 20/200 in the better eye.

StavrosK• 12 years ago

I've heard it described that blind people see what we see out of our left eye when we only have our right eye open. It's not blackness, it's just no perception.

inertia_lost2• 12 years ago

Similarly, I am almost entirely blind in my left eye and have been since birth. I have some very limited peripheral vision, but I can basically only sense light and movement in a very narrow field of view if I try very hard.

People have always assumed that what I see out of my left eye is basically what someone would see out of a normal, healthy eye with a big black spot in the middle, but that's not it. I don't see blackness, I see nothing.

einhverfr2• 12 years ago

Also since blindness is a lack of sight as we know it, it is a very large category of phenomenon. Someone who goes temporarily blind from a blow to the head may experience something differently from someone with retinal damage. Someone who has never been able to see may experience things differently from someone who has recently suffered blindness as a result of injury or illness (and these themselves might have different experiences).

jtheory2• 12 years ago

Right! I felt like no one was quite pointing this out.

Your brain is expecting certain input in given situations, and you have layers and layers of habits based on those expectations.

If you are accustomed to NOT having that input, you don't expect it. You don't fake it (imagining a black space of the size a visual field would be...), you just don't have it, and it's not a part of your interactions with the world.

If the shape of your visual field changes suddenly -- you're about to pass out and you get "tunnel vision" -- it's obvious and startling. If it changes gradually, you don't even notice; you just start hitting your head on low beams more often, or bumping into table edges as you go by, until you adjust (this is from experience...).

V-22• 12 years ago

I once read about a blind guy who got his eyesight - thanks to a surgery - after a life-long blindness of about 30 years. He did see, but couldn't process visual information like a normal person (eg. he would only recognize a human face to be a human face after the person began talking)

ygra• 12 years ago

I wonder whether that changes over time. After all, people with eyesight have to learn that as well, I guess. They just do it at the beginning of their life.

agumonkey2• 12 years ago

I am fascinated by the notion of color and tone. I suppose you're not deaf so you can feel tone (low and high pitch). I thought that these two 'abstraction' were conceptually the same and hardwired into our brain. But then there might be different roots for blindness and maybe childhood-blind people are having issues at that level (as opposed to eye / optic nerve level).

eru• 12 years ago

I still want that vibrating compass belt.

Lockyy• 12 years ago

I've also been really interested in using one ever since reading about them last year. Seems like it'd be a good Kickstarter opportunity.

baddox• 12 years ago

I wonder if it could be done more subtly, perhaps with a few vibrating motors embedded in the skin around one ankle.

gabriel342• 12 years ago

There is something similar to this that is already reality: people use a magnet on one finger to be able to perceive EM fields.

We have the ability to turn our senses off when we are going to sleep, so any "sixth sense" prosthetics should be switchable or at least not strong enough to disturb sleep.

Tyr42• 12 years ago

I think there was some work into this called "SouthPaw", to contrast with the external NorthPaw.

sp332• 12 years ago

There's a small version that goes on your ankle, called a North Paw. Get directions or order a kit here http://sensebridge.net/projects/northpaw/

joeyo• 12 years ago

If Google Glass (or its descendant) ever becomes viable, a killer app would be an augmented reality "this way is north" arrow that's always there, floating in the sky.

kaybe2• 12 years ago

I still want to try to glue a magnet to my finger. It is possible to get implants, but that's scary. Being able to feel magnetic fields must be awesome!

(http://gizmodo.com/5895555/i-have-a-magnet-implant-in-my-fin...

http://io9.com/what-you-need-to-know-about-getting-magnetic-...)

gohrt4• 12 years ago

Strange that the article doesn't mention the blind spot that everyone as.

http://en.wikipedia.org/wiki/Blind_spot_(vision)

pavanred• 12 years ago

I learned about the blind spot in my Visual Analytics course during my Masters. I wasn't aware of this phenomenon prior to that and it was fascinating to take the blind spot test and to learn that the brain interpolates vision for the blind spots using data from the surroundings, memory etc. so well that we never notice the blind spot.

I wonder if such a phenomenon occurs with people who lost sight during their life and aren't blind by birth, where the brain fills in the blanks based on memory.

spydum• 12 years ago

On the blind spot test, cover the other letter with your fingertip for same effect, and watch your finger disappear. For some reason this is far more impressive to me.

robhack• 12 years ago

Mind Blown. Not by the fact we have a blind spot, but how, like in the article it's not a black zone, but really the absence of any input that the brain tries to fill in. Now I'm curious to test how the brain interpolate on this area, like trying to put different background color or texture on each side of the blindspot.

Synaesthesia• 12 years ago

Having tested it, it seems to do a linear interpolation from the edges, often retaining the surrounding texture. Kinda like the smart fill from Photoshop

gd13• 12 years ago

I suspect you experience true blindness (briefly) during laser eye surgery, when the flap is cut in the cornea. I remember how odd it felt - the feeling of seeing nothing at all, not even darkness.

DigitalJack• 12 years ago

I could see after the flap was lifted. This was 2005 so I don't know the procedure anymore, but I was supposed to keep my eye trained on a flashing dot while the laser ablated my cornea.

gd13• 12 years ago

I meant when the blade goes into the eye. There were a few seconds after that before vision came back.

gd13• 12 years ago

Here's a reference, you downvoting HN twits:

http://www.realself.com/blog/terrible-lasik-surgery-complica...

"you have to pump the pressure up in the eye to about 6x normal in order to cut a good flap, as you can't cut an accurate flap in a floppy eye. The pressure is actually higher than your blood pressure, so the eye stops perfusing with blood, and you go temporarily blind."

steffan• 12 years ago

“When the belt experiment was over, Wächter felt lost”

It seems slightly cruel to me to give someone a device to augment their senses without some provision for them to continue using it if the experiment is successful.

I suppose it's also possible that Wächter didn't want to continue using / being reliant upon the belt despite the loss of the spatial sense it had provided.

gabriel342• 12 years ago

I think the experiment was still in progress when they took it away, since they observed his reactions to this. Later they might have given him the device.

bashinator• 12 years ago

I recall reading quite a while back about these ethical considerations - I'm pretty sure the ethics have been better taken into account with subsequent experiments.

Kaivo• 12 years ago

That reminds me of the experiment where someone lived with upside down goggles[1]. Just like with babies trying to understand what they see, his brain had to adapt to everything and he had to relearn to perform the actions.

I wonder how it was once he took them off.

[1] https://www.youtube.com/watch?v=-kohUpQwZt8

tokenadult2• 12 years ago

A very interesting take on the perceptions of blind people. I don't think I am acquainted with anyone who has been entirely blind from birth (which is a rare condition of life). I know a professor of psychology (who indeed does much of his research on human visual perception)[1] who has very limited vision, and thus is "legally blind." He began life, I think, with a bit more vision than he has now, but has long been visually disabled. In a personal conversation, he related that his originally intended research field was astrophysics, which of course can be studied by analyzing instrument readings from radio telescopes and other devices that don't necessarily have visual outputs. My wife is his piano teacher, and she has had to adapt her teaching to her first student who cannot read a printed musical score.

A much younger person I know who has very limited vision (and the prospect of declining vision as she grows up) attends summer mathematics programs with children running around playing soccer and Frisbee and seems to handle that with aplomb. To not even be able to recognize shapes or moving human beings, something that the blind people I know best are still able to do, would be especially challenging.

Aside: Have you all noticed that people who have acquired profound deafness that begins in adulthood have much less understandable speech than people with normal hearing? Apparently we all rely on feedback from our own senses to keep our speech behavior within the phonologically normal range of whatever language we speak as a native language, and habit alone can't maintain the fine tolerances necessary for readily understandable speech.

AFTER EDIT: Of course anyone can experience total lack of sight simply by going into a totally unlighted place. The human eye doesn't emit vision rays, after all (even though the ancient Greeks seemed to think otherwise), so if you are where there is no light, you see nothing with your eyes.[2] Studies on the human diurnal behavior cycle are sometimes done in deep caves with no source of artificial light.

[1] http://legge.psych.umn.edu/

[2] http://www.spring.org.uk/2008/03/50-of-college-students-thin...

http://www.npr.org/blogs/health/2013/10/30/241906619/seeing-...

pixelcort• 12 years ago

Originally from SF area, I have been living in Tokyo for over a year now, and since moving I rarely speak with native English speakers anymore. I've been told by friends and family on occasion my accent and grammar is slowly deteriorating.

tokenadult2• 12 years ago

The Americans I knew when I lived overseas for three years (on each of two stays that long) definitely had trouble with vocabulary retrieval, the more trouble the longer they had been away from native speakers of English. Correspondingly, Chinese people I know who have been away from places with lots of Chinese printed text often have a lot of trouble writing Chinese characters that everyone learns in school. Even "overlearned" skills that become second nature can degrade through lack of continued practice.

Swizec• 12 years ago

Similarly, I've spent a lot of time in the US lately and people can no longer really place my accent. It sounds neither native to here, nor what people from back home have.

Quite odd.

jarek• 12 years ago

Yes, this is common, due to lack of use. Though you should notice that you have much less trouble reading and listening than writing and speaking.

I immigrated right around the "easy"-language-acquisition barrier age and frustratingly can't speak either of my languages fully right - one because of leftover accent, one because of out-of-use vocab and grammar atrophy.

grownseed• 12 years ago

In regards to your aside, I essentially went through the opposite situation, i.e. I gradually lost my hearing as a kid (genetic condition) until I was completely deaf, and then got a bunch of surgeries which fixed the situation (until I lose everything again in about 15 years, or so I'm told).

In any case, my speech was affected in the way you describe. Most soft sounds started merging, e.g. 's', 'sh', 'tsh', etc. would all end up sounding like 'sh' coming from my mouth, and I had absolutely no idea that was the case. Similarly, I had no idea what the volume of my voice was, it'd either be really loud or really quiet, but rarely at the right level. My parents (mostly) told me I wasn't speaking properly (it took years before anybody realized I was going deaf, including myself), I ended up relying heavily on the vibrations I felt in and around my mouth/throat to correct these as much as possible.

Interesting aside to this aside, there exist implants for people who were born without a cochlea (the spiraly thing which "translates" vibrations). These implants are made of some alloy (not sure what exactly) which thankfully emulate a cochlea, but have the interesting side-effect of causing the affected people to speak with a fairly monotone and somewhat metallic voice.

jamesjyu• 12 years ago

This reminded me of the language of the Guugu Yimithirr [1] who always describe left/right/forward/back with cardinal directions. Thus, they always have a great sense of direction, and know where north is, even indoors. In that case, it's like the vibrating belt is built into the language.

[1] http://www.nytimes.com/2010/08/29/magazine/29language-t.html...

3pt14159• 12 years ago

A blind person once explained it to me:

I see what sighted people describe as "white". When I ask a sighted person what they see out of their elbow they typically get it. They see "nothing", but if pressed will usually say "static" or "white".

_bdog• 12 years ago

I have exotropia on one eye and completely lack binocular vision.

My right eye is my "main" eye (95%) and my left eye just submits the missing parts from the left that my right can't see because of the nose being in-between.

I always have the right side of my nose in my field of view, except that at the same time it's somehow not there. Like 50% opacity. The left side of my nose isn't visible.

When I "hide" a finger behind my nose for the right eye and look in it's direction it's gone. When I stare straight forward, it appears again.

(My) vision is weird :).

dkresge• 12 years ago

I was born (40 some odd years back) with an underdeveloped optic nerve in my left eye. An early surgery for Amblyopia corrected my gaze, but those first years of wearing a patch over "my good eye" resulted in nothing more than a lot of stress for my folks. And while I attempted to explain what I could see (are they shadows?), I never really had an answer as to why I could count "how many fingers" someone was holding up. Curiously, it was only within the past few years that I realized my left eye renders what one perceives peripherally. Hold your hand to the side of your head -- it's there, but do you really _see_ it? I can't imagine putting blindness into words.

inertia_lost2• 12 years ago

Wow, I think you might have a very similar vision issue as I do!

Left eye as well, although my eye is healthy, it was closed when I was a baby so my vision never developed properly. Eye patching was tried on me as a kid, but just resulted in a cranky toddler me. It took years and years for me being able to verbalize what I could see out of my left eye--I basically have some limited peripheral vision and no central vision. My eye doctor explained that part of the issue is that peripheral vision primarily detects motion while central vision is for detail--so while I can detect motion and light, it's hard for me to put an image together.

I have so many memories of trying to read that big stupid E with my left eye and not being able to explain what I saw. (Um, there's a light on, right?)

bramd5• 12 years ago

First of all, be aware that the group that's actually totally blind is relatively small. Most people who are legally blind have some form of light perception, or can see something. I've been totally blind since birth.

Blind people can have a good or bad sense of direction, just like their sighted peers. I think the device described in the article might be more useful on short distances and less relevant for knowing where your home is while you're far away from it. This because blind people don't have the visual queues to determine if they're walking in a straight line for example. Getting immediate feedback could help with such skills and learn them how to verify the signals from the device with other senses.

Sensory substitution, aka how to replace input from one sense with input from another is a quite interesting topic.

eranation2• 12 years ago

I've been totally blind since birth.

Please forgive me for the naive question, I'm probably full of misconceptions about blindness, but out of pure curiosity, how do you read and write so well without seeing? Is the technology so advanced today? Are you using a screen reader and a regular keyboard? (e.g. typing and than playing it via the reader) how do you know if you made a typo? (e.g. who's and whose sound the same)

You really didn't have any typos, and as well your indentation and styling are perfect (much better than me but I'm not a native English speaker)

Can you read and write code without seeing? Are there any blind programmers that you know of.

again asking out of pure naivety

tl;dr, I'm impressed with your reading and writing considering that you said your are totally blind, and curious how do you do it. (I always was afraid of going blind for some reason, and afraid I will never be able to write code again)

gohrt4• 12 years ago

TV Raman has done a lot of work and storytelling relating to his blindness. He is a CS researcher at Google:

http://en.wikipedia.org/wiki/T._V._Raman

bramd5• 12 years ago

I'm not a native English speaker either.

Is the technology so advanced today? Are you using a screen reader and a regular keyboard? (e.g. typing and than playing it via the reader) how do you know if you made a typo? (e.g. who's and whose sound the same)

Yes, I'm using a regular keyboard and a screenreader. Besides speech output I use a device called a refreshable braille display which can display up to 40 or 80 characters at a time depending on the model being used. I'm sure you will find some pictures if you Google it. However, those devices are quite expensive and many blind people just use speech output. Even with just speech there are options for reading letter by letter, word by word etc. However, I see some people make much spelling mistakes because they just listen and not rreally read how a word is spelled.

Can you read and write code without seeing? Are there any blind programmers that you know of.

Sure you can. I make a living by programming and doing web accessibility consultancy. Another nice example is the free and open source NVDA screenreader[0], which is developed by two blind guys.

[0] http://www.nvaccess.org/

leoc2• 12 years ago

Sensory substitution, aka how to replace input from one sense with input from another is a quite interesting topic.

Indeed! Have you ever tried something like the vOICe http://www.seeingwithsound.com/ ?

bramd5• 12 years ago

Have you ever tried something like the vOICe http://www.seeingwithsound.com/ ?

Yes, I have played with it. However, I'm not convinced yet if I should invest a lot of time learning it. Another useful and interesting skill is echolocation[0]. I have used that since Iwas a child to survey my environment.

0: http://en.wikipedia.org/wiki/Human_echolocation

joedevon• 12 years ago

Tommy Edison, the Blind Film Critic's take: https://www.youtube.com/watch?v=ZDHJRCtv0WY

janus• 12 years ago

This story reminded me of the guy that had a magnet implanted in his pinky finger, who was then able to sense electromagnetic fields and other stuff

http://gizmodo.com/5895555/i-have-a-magnet-implant-in-my-fin...

gohrt4• 12 years ago

Implant seems extreme. One could do well with, say, compass armbad with a strong magnet and a pokey attacmhent.

tempestn2• 12 years ago

This made me realize that while it is instinctively difficult to imagine a lack of sight or touch, a lack of sound, smell, or taste, seems relatively easy to imagine. Sight vs sound is especially interesting; we tend to think of lack of sight as blackness, as the article describes, but there doesn't seem to be an instinctive parallel for lack of sound (at least in my mind). I guess it would be "silence", but that's much more akin to lack of sound than the concept of blackness is to lack of sight (even if blackness is technically lack of light).

Although having written that, I now wonder whether a person who loses their hearing might be plagued by phantom hums or such things, as can sometimes happen to hearing people when exposed to extended silence.

dicroce• 12 years ago

They see what you see out of your elbow.

icantthinkofone• 12 years ago

Many years ago, blind people might put their hands on your face to help them get a sense of you. A blind friend of mine, Jim, got in the car with us, one night, and sat next to a friend he did not know. He put his hands on the other guy's face, then paused, then said, "Man, you are uuuuuugly!".

tylerpachal• 12 years ago

For me this raises a question on a slightly different topic: if you're born deaf, what languages do you think in? I can consciously think in English and French, but if you have never heard a spoken language before, what would your thoughts be like?

mkoryak• 12 years ago

A couple of years ago I read a non-fiction book called Crashing Through[1] - about a guy who was blinded by some chemical at a very young age (<1y) and was able to have his vision restored in his 40s via a new procedure.

It went on about some difficulties he had processing the new data. His brain had to "learn" how to see. It was so difficult that he would sometimes close his eyes and and rely on his echolocation skills to navigate.

Very interesting book if you want a first hand account of what it is like to go from being blind to being able to see. (and also about being blind)

[1] http://www.amazon.com/Crashing-Through-Extraordinary-Story-D...

pje• 12 years ago

Herzog's Land of Silence and Darkness [0], which follows some elderly members of the German deaf-blind community, is one of the most fascinating documentaries I've ever seen. One quote in particular has stuck with me since I saw it years ago:

“People think that deafness means silence, but they are wrong. It is a constant noise that ranges from a gentle whisper going through some cracks to a constant buzz, which is worse.”

[0] http://en.wikipedia.org/wiki/Land_of_Silence_and_Darkness

deanclatworthy• 12 years ago

A great article. I recently visited the "Blind Exhibition" in Warsaw. They show you some items that blind and visually impaired people use on a daily basis and then you have to guess what they are for. I'd never contemplated how blind people know when a coffee cup is full, or pair their socks.

They then take you into a series of rooms (bathroom, the street, art gallery, kitchen etc.) which are completely black. Not a shred of light. You are blind. I can't describe how it felt other than terrifying. I didn't know if my eyes were open or not. It wasn't the black that I saw when closing my eyes, or am sleeping in a dark room. It was this empty hollow of nothingness.

As someone who has always wondered what it's like to be blind then closed my eyes for a few minutes and stumbled around my home - it's nothing like that at all. I left having found a new sense of understanding for the struggles that blind and visually impaired people go through on a daily basis.

An interesting but harrowing statistic they mentioned at the end of our trip was that the majority of people go blind, instead of are born blind. And the main cause is diabetes. It's not uncommon that those with diabetes lose their sight and then their sense of touch. Imagine not being able to feel your way around after going blind.

I highly recommend the exhibition if you're ever in Warsaw, and I think they have it in a couple of other cities: http://niewidzialna.pl/en/

tallanvor• 12 years ago

I'm mostly blind in one eye. --The center of the pupil was destroyed by a parasite when I was very young, and I have no memories of normal sight. I do have some peripheral vision in that eye, but not enough to read or perform normal activities, especially because I have to turn my head to see, such as it is - I can make out certain objects and get a sense of colors, but nothing is clear - reading would be out of the question, for example.

Describing my lack of sight is difficult, because few people have the necessary frame of reference to understand. The best way I've found to describe it is to say that I can only see one side of my nose. Now, I know the other side is there, obviously, because I can look in a mirror and see it with my good eye. But without a mirror, that side of my nose doesn't exist to my vision. --There's not a dark blob or anything like that - it simply does not exist.

It also means I have no real depth perception. I have to try and estimate the distance of an object based on what I know of it's true size - when it's moving towards me, I don't get a real sense that it's actually coming at me, just that it's getting larger at some rate. Needless to say, that makes playing games like baseball very diffciult as there is not necessarily other objects around that make it easier for me to recognize the rate at which the ball is flying towards me.

cmiller1• 12 years ago

Can't you move your head side to side to judge depth by parallax movement? At least a little bit?

exch• 12 years ago

Having congenital Glaucoma, I've always had to live with the possibility of one day being blind. My left eye is already pretty much there.

What has always fascinated me about sight is how our brains augment and outright invent things you think you see with your eyes. It's not at all about believing what you see, but about seeing what you believe.

The Glaucoma has steadily been eating away at my retina and optic nerves over the many years. Causing blind spots to form all over my visual field. In daily life, I can't see those spots. As in, there are not actually black holes in the images I perceive. The brain somehow manages to fill in those gaps with visual information directly surrounding those gaps and combine it with what my experiences/memories tell me should be there.

It's only when I start concentrating on really small details, that these holes become apparent. Particularly when looking at small LED lights in a dark environment. The LED keeps disappearing and reappearing as I slowly turn my head in various directions. Everybody has a single blind spot like this in the center of their visual field which behaves in the same way. Imagine this, but multiplied over 60 - 80% of your visual field.

Additionally, my almost-blind left eye has caused me to lose depth perception all together. This means those fancy stereoscopic 3D things are pointless to me and one would expect I would have a hard time in traffic. Not being able to judge the distance to an oncoming car can be deadly. But again, the brain seems to draw on its memories and years of experience and somehow manages to account for the lack of depth perception. It's not perfect, but enough to cope in daily life and safely move from A to B. At least on foot, that is. I am not allowed to drive a car for obvious reasons. A moped is technically permitted, but I don't. It moves too fast for me to accurately judge my surroundings in time. The same even goes for a bicycle. I only ride those in daylight. Not at night.

As far as blindness goes, I've had this once. As a kid, I fell out of a tree and landed flat on my back. For the following 45 minutes I was completely blind. It freaked me out to no end, as I was terrified it would not go away. Luckily it did. Not looking forward to that again!

netcan• 12 years ago

There's an analogy I like to bring up. I don't remember where I heard it, but It would be great to find a better articulation, but here it goes.

Gregor Mendel is called "father of modern genetics" for his work on plant hybridization and discoveries in the area of hereditary traits. He's called that because he described "invisible factors" producing "traits." We would now say that he discovered genes and their expression.

Around the same time Charles Darwin produced his great works on evolution. He was also essentially relying on invisible factors inherited from previous generations producing discernible traits in subsequent generations. He went beyond that and hypothesized about how constant sexual and natural selection would allow certain traits to be more common in the species as a whole.

Both of these men were essentially studying and describing genes, geneplexes & DNA. But, DNA was unknown to them. They knew that traits are handed down from one generation to another. But, if you asked them what the physical form of these traits was, they would have no answer.

DNA & Genes were not observable to them. They had placeholders in their mind. I guess they new that the seed produced by the parent plant contained the traits, but they might have also used "spirit" or "essence" as their placeholder.

We are at this stage when it comes to cognition. We don't know what a thought, memory or emotion looks like. We don't know what their physical form is. We know it has something to do with neurons and the brain, but we don't really know the how and what.

There is an obvious hole in our knowledge. It' missing in discussions like this.

xenophonf• 12 years ago

Katawa Shoujo actually addresses this in-game. One of the game's characters, a blind woman, describes her dreams including sensations from her other senses: smell, taste, touch, hearing. As something I have wondered about, I was really pleased that the game's authors thought of this.

What Do Blind People Actually See?

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