What Happens When Blind People Get Vision Correction?

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"The brain comes prepared to perceive the world. When babies are born, the optic nerve (which carries signals from the light-sensitive retina at the back of the eye) connects to a nucleus in the thalamus, and, from there, connections go to areas of the brain’s cortex that are responsible for processing visual information. Although this wiring is built in, the areas of the brain need input in order to organize in ways that actually allow the visual world to be perceived.

Visual Memory

An amazing thing about the visual system is that it supports incredible visual memory abilities. You are able to recognize large numbers of objects based on brief visual input. You are also able to remember which objects you have seen recently and to differentiate them from other objects you have not seen, even if you only view them briefly.

What would happen to your brain, though, if you did not get early visual input? For people who are blind from birth, their retinas never carry information about the visual world back to the brain, and, so, the brain is unable to organize in a way that would support visual perception. Suppose, though, that a blind person suddenly got the ability to see. Would the brain then adapt to this input and create the same kind of amazing memory abilities that people with sight since birth have?

Study of Patients With Congenital Cataracts

They engaged with a project in India that provides surgery for congenital cataracts that emerged before the age of 1 so that these individuals functionally had no sight since birth. These patients received the surgery on average when they were 13 years old. Their performance was compared to that of a group of normally sighted children of a similar age. These participants wore lenses that blurred their vision to simulate the level of visual clarity that the patients would have after surgery.

Results at 12 Months After Surgery

By the time the participants were 12 months after surgery, their performance on the memory test was just as good as the normally sighted individuals whose vision was blurred.

This research suggests that the brain is able to adapt to getting visual input, even after 10 years of blindness. That said, it takes a little while before this ability to really process the images kicks in. Right after the second surgery, patients are getting input to the brain from their retinas, but their visual memory is still poor. After about a month, though, the brain has found ways to process this visual information, and, a year later, their brains do just about as well as those of people who had sight from birth."

Read the full available article on Psychology Today

Reflection: Do you know someone who has gotten a vision correction and being able to see prior to being blind?

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