Blindness. Do you see black, or nothing?

Probably only people who have been blind and can see afterwards or people who can see and then get blinded afterwards can correctly answer this but what do you think?
I am talking about people who have been blind all their lives and have never expierienced color.
Is everything black for them? That doesn't make sense since they don't have color perception. It doesn't exist. They probably don't see anything at all but how does that work? I can't really comprehend that. What do you guys think?


Have a nice day,
Ginsan

I believe that if you are completely blind, you simply do not see. This is because sight is caused by the connection between your eyes and your brain, your eyes receiving data from the external world in the form of electrical signals which are interpreted in the brain to see something. This means that sight is effectively from inside of your own head, but you must have some kind of connection to your eyes to be able to "see" anything. It would be like asking "What color do you see with your big toe?" because the eyes would be as effective at seeing as any other body part. However, being completely blind is very rare and most people just have severe lack of sight to the extent where they will only be able to see extremely harsh lights. Sometimes people who are totally blind will see flashes of light/colour produced by their brain, similar to what happens when you look at a bright light or bang your head.

However, people who have gone blind after a period of being able to see do actually dream of colours and people as if they could see again whereas people who have always been blind have a heightened sense of touch, taste and every other sense that is intact while dreaming. An interesting concept :)

I suspect that the only way to answer that question would be with an extremely thorough knowledge of how qualia are produced by the nervous system, and an extremely detailed picture of an individual's CNS.

I've heard anecdotes of people who have been blinded being able to see in dreams, and don't see any reason why they wouldn't see blackness given that they already have the concept of colour, unless there's been severe trauma to the appropriate region of the brain.

I also seem to recall a case of someone being 'cured' of blindness, but their brain was completely unable to interpret the information.

Imagine it like how you imagine how sharks sense electrical stimuli in the water, or how birds have magnetic senses (giving them the ability to navigate). Are you able to truly comprehend how this could possibly be sensed? Not at all, I imagine it isn't as simple as "seeing black". It's more like being totally oblivious to sight the same way you are to magnetic forces or small amounts of electricity in water. It's incomprehensible.

This guy has been blind for all his life. He has many videos in youtube regarding blindness: see his videos about what he sees:

http://www.youtube.com/watch?v=ZDHJRCtv0WY

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Originally Posted by snoop

Imagine it like how you imagine how sharks sense electrical stimuli in the water, or how birds have magnetic senses (giving them the ability to navigate). Are you able to truly comprehend how this could possibly be sensed? Not at all, I imagine it isn't as simple as "seeing black". It's more like being totally oblivious to sight the same way you are to magnetic forces or small amounts of electricity in water. It's incomprehensible.

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Well that's interesting.. First I was like, birds just have a magnet inside their head so when it moves because of earth's magnetic field they get sensory information and they can navigate and sharks just have some material that responds to electrical charge, and they get sensory information from there. But when I think about it, I can't comprehend it at all.. Just like I can't comprehend the lack of vision

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Originally Posted by zoth00

This guy has been blind for all his life. He has many videos in youtube regarding blindness: see his videos about what he sees:

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Yeah I know, this guy is hilarious xD He said 'It's (not seeing) really hard to get your head around. See, that would be like me trying to get my head around seeing' Well, he's got a point :P But he also said that he can see whether something is light or dark. If the sunlight is pouring into the room, he knows it is light. If it doesn't, he knows it is dark. So there must be some hard-wired stuff in the brain and eyes going on that makes that possible. Because he does perceive it. So he understands the concept of light and can actually perceive it. But not of color. That's funny, isn't it? It makes me wonder about the difference between light/dark and actual color

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Originally Posted by Ginsan

Well that's interesting.. First I was like, birds just have a magnet inside their head so when it moves because of earth's magnetic field they get sensory information and they can navigate and sharks just have some material that responds to electrical charge, and they get sensory information from there. But when I think about it, I can't comprehend it at all.. Just like I can't comprehend the lack of vision


Yeah I know, this guy is hilarious xD He said 'It's (not seeing) really hard to get your head around. See, that would be like me trying to get my head around seeing' Well, he's got a point :P But he also said that he can see whether something is light or dark. If the sunlight is pouring into the room, he knows it is light. If it doesn't, he knows it is dark. So there must be some hard-wired stuff in the brain and eyes going on that makes that possible. Because he does perceive it. So he understands the concept of light and can actually perceive it. But not of color. That's funny, isn't it? It makes me wonder about the difference between light/dark and actual color

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Well the reason we can detect colours is because of waves of light with different wavelengths. The length of the wave determines what colour we would see that light as so the fact that he can detect light but not colour shows that there may be a problem with the part of his eye that receives the information that is colour or that there is a problem with his brain interpreting the colour. This should not be a surprise as the majority of his vision is not functional.

The difference between light and dark:
Light - A source is emitting light allowing us to see our surroundings.
Dark - The absence of any light/light source.

The most obvious answer would be that they see black. The eyes are just a sensory device. The actual turning of the data into a picture occurs in the visual area of the brain. People who have been blind from birth but are later healed do not understand how their vision corresponds to the spacial scene, but they do see the colours of the scene before them. So it stands to reason that before this moment, they were experiencing a field of vision corresponding to no data from the eyes... so, blackness.

A different question is what somebody with no visual centre would see... but it seems fairly obvious that they would have no kind of visual experience at all.

I wonder if, without eyes, you'd be more in touch with your pineal gland and would still be able to sense light and dark. I wonder to what level we would sense light and dark with our pineal gland consciously, were it's light receptors not washed away by our eyes.

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Originally Posted by Original Poster

I wonder if, without eyes, you'd be more in touch with your pineal gland and would still be able to sense light and dark. I wonder to what level we would sense light and dark with our pineal gland consciously, were it's light receptors not washed away by our eyes.

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What's a pineal gland?

A gland in the brain that produces melatonin which regulates sleep cycles and eliminates free radicals (fights cancer). It uses ocular rods and cones to determine if the setting is dark enough to release melatonin, hence it's more commonly known name, the third eye.

Pay no mind if this is a stupid question, but why would a blind person "see" a black void rather than all white? I always assumed it'd be like when you're losing consciousness and you start seeing white stars and they get bigger and bigger until everything goes white for an instant (and then black).