They once were blind but now they see. Which begs the question — what exactly do people see when they gain sight for the first time? Often, it's terrifying.
What
happens when people first really look at the world? Generally, we don’t
know. They’re far too young to tell us what’s going on in their mind.
By the time children are old enough to articulate what they see, they
don’t remember what the world looked like in their first few weeks of
life. There are special occasions, though, when full-grown adults can
see for the first time. For the most part, they see a complete
confusion. Often, that does a lot of emotional damage.
One of the
earliest-known cases of regained sight is Virgil, the Roman poet. At
age fifty, he had cataract surgery and regained his sight. Soon after,
he wished he hadn’t. This is common to many blind people who regain
their sight. Unlike infants, who are catered to, whose brains are
primed for learning, and who have no option but to learn, blind people
are asked to replace a familiar sensory system that reliably guides them
through the world with an unfamiliar one that does nothing but confuse
them. Sometimes the strain of assimilation is too much. Like many
other patients, Virgil would shut his eyes and pretend he was still
blind when the situation became overwhelming. He became depressed and
died of pneumonia soon after his surgery. Although he had seen the
world with his eyes, he retained his “mental blindness,” or what experts
call “visual agnosia.”
For someone
to see an object, the eye needs to pick it up, but the brain also needs
to recognize it. This process takes both practice and a certain
physical ability in the brain. Agnosia patients have generally suffered
brain injuries and lost the ability to understand what they see – they
see a rectangular object with a brown circle on top and a loop on one
side, but don’t understand that they’re looking at a cup of coffee.
There are only shapes. Those who have been blind most of their lives
“wake up” with a certain amount of visual agnosia.
Spatial
distance is often the primary problem they run into. One man saw people
walking away from him as inexplicably shrinking. Another would
practice spatial recognition by going out in a field and throwing his
boot as far as he could. He’d hold out his hand to grab it, and if it
wasn’t in reach, step forward before trying again.
Another
area that many newly-sighted people find inexplicable is paintings and
other visual representations. They can comprehend real objects, but not
painted ones. When they do understand what the paintings are
meant to represent, the shadows that are meant to define space and give
shape just look like dark marks on the painting. Which, technically
they are. It's only a willful visual laziness on the part of the
sighted that lets us see these paint blotches as shadows rather than
shapes and colors.
Because we
develop familiarity with faces and facial expressions at specific times
in our lives – those who are deprived of human contact or changing
facial expressions at that age often have trouble reading expressions
for their entire lives – formerly blind people are often face-blind, or
unable to decipher emotion from facial expression. Some have trouble
differentiating between male and female faces.
Which isn’t
to say that these people always have a completely blank slate,
visually-speaking. It’s been shown that when blind people read Braille
the visual cortex activates. They “see” with their brains, just not
with their eyes. Surgeries on children are particularly successful.
One doctor was surprised to find that a ten year old was coordinated
enough to catch paper balls thrown at him only a few weeks after
surgery, and knew the medical staff by sight. Young people assimilate
the world very quickly.
In one
famous case, a man regained his sight after being functionally blind
since the age of ten months. (He was able to point at bright objects,
but nothing more.) He had worked with machines and mechanics, and was
able to read the clock in his hospital room shortly after recovering
from surgery. The shapes, however unfamiliar to his eyes, made sense to
his brain. He was also able to find his way around the room,
coordinating what he saw with distances that he had walked before
surgery.
When psychologists asked him to draw what he saw, starting with people, his house, and a bus, his drawings were quite extraordinary.
They began as simple shapes. Houses were perfect squares with square
windows and a rectangular door - the way a small child would draw a
house. His buses were similar, squares and circles. As he developed,
he added more detail to the design of the bus, including the text on its
signs, but forgot to add parts of the outline of the bus, so that
windows and wheels appear to be floating. He can draw people, in a
symbolic way - two arms, two legs, and a head with all the features.
When asked to draw an elephant he drew a smeared gray shape with four
legs and tubes for both head and tail. Once he couldn't represent the
object with shapes or features that he knew had to be there, he couldn't
recreate it.
Learning to
see is, in many ways, like learning to read. It’s a complex process
involving time, practice, and mental ability, but it’s a process that
only works one way. At some point we lose the ability to look at a
“stop” sign and not automatically read the word "stop" – but at least
not understanding the written word is imaginable. The idea of not
understanding that a stop sign is a sign, or that it is a solid object
placed in front of one thing and behind another, reaches too far back
into our history. We have to look at others to understand what the
world looks like before we connect “looks” to the world.
Source : io9.com
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