It is common for a person with excellent eyesight to wonder what blind people see. Blind people, in turn, are interested in whether all blind people have the same perception of the world, or some perceive the world differently, or maybe even see something.
There is no universal answer to the question of what blind people see. First, there are varying degrees of blindness. Secondly, since they "see", that is, they process visual information, not the eyes, but the brain, the fact of whether a person has ever seen in his life, or was born blind, is of great importance.
People born blind
A person who has never had sight does not see anything, because he simply cannot see.
Samuel, born blind, during an interview answered questions about how he perceives the world around him. He argues that the expression that a blind person sees the world around him as black is not at all true. The fact is that a person blind from birth simply does not know what blackness is, he has nothing to compare it with. He quite seriously sees nothing, sees emptiness.
This is difficult for a sighted person to understand, but imagine what you see with your elbow. Nothing, right?
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Another helpful exercise is to close one eye and use the open one to focus on something. Now answer, what does your closed eye see?
People completely blind
People who have completely lost the ability to see have a different experience of perceiving the world.
Some describe total darkness as being in a dark and deep cave. Some people see bright sparks or experience vivid visual hallucinations. These hallucinations can take on recognizable shapes and colors.
Charles Bonnet syndrome
The processes of perception of random shapes, colors or flashes of light with complete loss of vision are symptoms of Charles Bonnet syndrome. This syndrome can be long-term or it can manifest itself in short periods.
Charles Bonnet syndrome is not a mental disorder and is not associated with brain damage.
Functional blindness
In addition to absolute blindness, there is also functional blindness. Definitions of functional blindness vary by country or medical organization.
In the United States, functional blindness is a visual impairment when the best eye, already with maximum correction, sees worse than 20/200. The World Health Organization defines blindness when the best eye, under optimal conditions, sees no better than 20/500 with less than 10 degrees of vision.
What functionally blind people see depends on the severity of the blindness and the form of the impairment.
Legal blindness
The person may be able to see people and large objects, but they are out of focus. A legally blind person can distinguish colors or see objects at a certain distance (for example, they can count fingers right in front of their eyes).
In other cases, a person loses the perception of colors and sees everything as if in a thick fog. In cases of legal blindness, symptoms of Charles Bonet syndrome may also appear.
Light perception
Sometimes people with functional blindness can have light perception. That is, even if a person does not see anything, does not distinguish colors and shapes, he can say whether it is light around or dark.
Tunnel vision
With tunnel vision, a person loses the ability to see the periphery. In a certain narrow radius, a person's ability to see the world around him with tunnel vision can be quite good, but the periphery is black. In fact, a person sees only what falls on the central part of the retina.
What do blind people see in their dreams?
A person born blind has dreams but does not see images. The dreams of people who are blind from birth consist of sounds, tactile information, aromas, tastes, feelings and sensations - everything that they perceive in reality.
On the other hand, a person who has lost their eyesight during their lifetime may have dreams with images and visual information.
The expression and perception of objects in dreams depends on the type and history of blindness. In fact, all people in a dream see the world as they are accustomed to perceive it in reality with the range of vision that is inherent in a person throughout life. For example, a person with color blindness will not be able to see colors in a dream, even if they really want to.
A person whose vision has deteriorated during his life may see in a dream clearly, as before, or blurry, as now. The same goes for people who wear corrective lenses: they dream both clearly and blurry. Even visions caused by Charles Bonet syndrome can become part of dreams. In fact, dreams are a reflection of reality.
Interestingly, the rapid eye movement that characterizes REM sleep occurs in some blind people, despite the fact that they cannot see images in their sleep.
Cases in which rapid eye movement is absent during REM sleep include loss of vision at birth or at a very early age.
Perception of light in blindness
Some experiments conducted with completely blind people confirm that, despite the lack of perception of visual information, they are still able to react to light.
Evidence of this began to emerge during a 1923 research project conducted by Harvard graduate student Clyde Keeler. Keeler bred blind mice that, due to a certain mutation, lacked retinal photoreceptors.
Despite the fact that mice did not perceive visual stimuli, their pupils still responded to light. In addition, the mice adhered to circadian rhythms established by round-the-clock day-night cycles.
Eighty years later, scientists have discovered special light-sensitive cells related to the retina of the eye, more specifically to the nerve node (ipRGCs). These cells are found in both mice and humans.
The ipRGCs are found on those nerves that carry signals from the retina to the brain, not on the retina itself. Cells react to light without contributing to vision. Thus, if a person has at least one eye capable of perceiving light, regardless of the level of vision, he is theoretically able to distinguish between light and darkness.
Hope Chikanchi