what is sight to a blind person?

[ZeroZero]

This question has just occureed to me and i find it interesting. Assuming a person is blind from birth, how do they understand sight in their own mind. I know a superficial answer is easy to ascribe, but looking a little deeper, are there any common mistakes that a blind person might make, are there forms of cognition (not perception but cognition) that consequently become unavailable. I know for example that a pianist has a certain advantage as they can only locate the keys without the use of sight, where a sighted player (and I am one) can only seem to look at one hand or the other. If the habit of finding a finger position in one hand is triggered by vision then if you look at the other hand this trigger is lost - unless one develops panoramic vision of both hands simultaneously.

Is quantity harder to understand for example in developemet of the brain? Are blind people better or worse at math? Is the notion of perspective difficult to grasp? We use this term psychologically as well as practically 'metaphorically if you like?

 

Obviously non verbal expressions would be unavailable, does this impair emotional development. It seems to me not so, but then why not so?

 

 

 

I googled this but there seems ot be little discssion. It would be interesting to see a birth-blind person being interviewed regarding their opinion on sight

 

 

 

Anyoe care to comment?

[Domnik]

Working in a Pharmacy I've dealt with a lot of blind patients,

 

And they all seem to say the same thing, all they see is black. Black and a mixture of colors kind of what you would see if you had your eyes closed or if you were sleeping..

 

I suppose it makes sense since when you close your eyes there is no light being reflected into your retina, so without the capability to see you won't really have any light being

reflected in there too!

[ewmon]

I don't know how the naturally blind could naturally understand sight, but I can say how I could explain it to them.

 

It's like having tiny strings attached to every part of every object, and they are connected to the eyes. Your eyes sense the direction the strings come from.

 

A closer object blocks strings from a farther object that's "behind" it.

 

As objects traverse your field of vision, the strings follow them.

 

As an object approaches, the angular "size" between the strings increases. When you see the angular sizes increasing for the whole object, you can either figure that it's expanding like an inflating balloon or it's moving closer to you. The opposite occurs when the angular size decreases. This can be easily demonstrated by placing an object between adjacent, straightened fingers (or chopsticks, knitting needles, etc) and moving it toward the hand or fingertips. Binocular depth perception can be explained with triangulation. Binocular depth perception should change appropriately with angular size changes; otherwise, the object is either inflating or deflating.

 

Color can be information in the strings such as amplitude and frequency of vibration, about one octave of six notes for the standard colors (red, orange, yellow, green, blue, violet) and off-note frequencies for all the colors in between. White is all the colors "sounding" together (like "white noise" ... hmmm), black is "silence". Color intensities as well as highlighted and shaded parts of objects can be explained with amplitudes.

 

TV, videos, photos, paintings and drawings are flat surfaces with these strings coming out as if the objects were behind the surface. Your binocular depth perception tells you that the surface is flat, thus the illusion of depth tricks your eyes only with angular size and overlap. However, lack of binocular depth does not spoil the illusion all that much, especially if it is depicting something of interest, like a loved one's face.

Edited July 21, 2012 by ewmon

[Joatmon]

My first thought was "find a blind person and ask them". Then I realised that if we can't really imagine what a blind person "sees" then a blind person will have great difficulty imagining what a person who is not blind sees. For both parties comparison is not really possible (IMO). I am thinking of people born blind. How, thinking of a different sense, might you be able to describe the taste of something to someone who had never had a sense of taste? Words like bitter, sour and sweet would hardly have meaning.

[Hooman]

Working in a Pharmacy I've dealt with a lot of blind patients,

 

And they all seem to say the same thing, all they see is black. Black and a mixture of colors kind of what you would see if you had your eyes closed or if you were sleeping..

 

I suppose it makes sense since when you close your eyes there is no light being reflected into your retina, so without the capability to see you won't really have any light being

reflected in there too!

 

I think that might be the case with those people who weren't born blind and I presume that you have came across this group of blind as you have pointed out that they refer to colors and I don't think the born blind would be able to tell what color black is.(or maybe what color is at all for that matter)

But the real question lies in relation to born blinds.

 

PS: Is "born blind" a legitimate combination of words to use here? If not please correct me.

[DrmDoc]

I think that might be the case with those people who weren't born blind and I presume that you have came across this group of blind as you have pointed out that they refer to colors and I don't think the born blind would be able to tell what color black is.(or maybe what color is at all for that matter)

But the real question lies in relation to born blinds.

 

PS: Is "born blind" a legitimate combination of words to use here? If not please correct me.

 

I think words you are looking for is congenital blindness. I hope this helps.

[Weirdmaskman]

Sight to the blind, specifically, the born blind is a difficult thing to assume.

Since its congenital and hard to describe somethings to them to be able to picture it in their gloomy vision, such as colors, the only option they have is the magic during the REM (dream). There, they may get an idea of the whole thing (thats if the format of their dream is HD Video and not just Audio i.e thats if they see anything in their dream)

What is there to cogitate in colors?

Another likely thing is their power of perception and ability to merge and correlate it with Imagination

[Derin]

I can't comment on the subjective experience of blind individuals, but if their blindness is the result of eye problems and not brain damage, their visual processing usually works fine, it simply lacks data. So I would hazard a guess that they should be able to conceptualise the world in the same way we do, albeit with less detail. The area of the brain that we use for visual processing is what some blind people use for acoustic wayfinding, and is also used by the tongue visual aids pioneered by Bach-Y-Rita. (Subjects who could previously see described also the tongue device input as similar to sight once they became accustomed to using them.)