What Do Visually Impaired People See?
23 June 2016
It sounds like a simple question–what do visually impaired people see? Yet as humans, our reality is so visually oriented, it is hard to imagine what a non-visual world could be like.
Turns out visually impaired people can indeed “see,” just not the same way we do.
Types of Impairment
There is more than one answer to what visually impaired people see because there is more than one type of visual impairment.
Some people are considered “visually impaired” who can still perceive light and shadow, some used to see but went visually impaired so their brains remember visual input, some are considered legally blind but can still make out large objects and familiar people.
The following will attempt to answer the question of what people who have been completely visually impaired since birth see.
Understanding what it would be like to be visually impaired
Many people when they try to imagine what they would see if they became visually impaired just close their eyes. But even with your eyes closed, your eyes still see blackness.
For those who have been visually impaired since birth and have no visual input, they don’t see black or white–they see nothing. To perceive this, imagine what it “looks” like at the back of your head.
So How Do They ‘See’?
This is where it gets really tricky. It turns out visually impaired people can use their other senses to create a detailed 3D map of the space around them. Research suggests that even the brains of people born unable to detect visual stimuli still interpret certain information as visual.
A study from the Hebrew University of Jerusalem determined that visually impaired people can learn to “see” the shape of a human body using only their ears similar to how bats and dolphins use echolocation to “see.”
Brain scans later revealed the visual cortex of the test subjects lit up during these tasks. Neuroscientists normally refer to the “visual” cortex as the area of the brain responsible for processing visual data, but for visually impaired people, sound information routes through the visual cortex as well creating spatial maps.
According to the World Health Organization, around 40 million people worldwide are blind, while another 250 million are visually impaired. As ageing populations are on the rise, and with them age-related disorders such as glaucoma and diabetes, it is more important than ever to understand what it would be like to be visually impaired in order to best help those with severe visual impairment.