Boy Missing Vision Part of the Brain is Still Able to See in Medical Mystery Baffling Scientists

Ocularist Gerhard Greiner holds a glass tube over a bunsen burner. Researchers have presented a study of a boy without the visual center of his brain who can still see. Michaela Rehle/Reuters

A 7-year-old boy missing the part of the brain responsible for vision can somehow still see, scientists in Australia have found.

The boy, known as "BI," was born with a rare metabolic disorder that caused him to lose use of his visual cortex, which usually processes electrical signals from the eyes. However, the team from the University of Melbourne found that the boy is able to see well enough to play games and recognize people, according to New Scientist.

A group of researchers have studied the child, and presented his case at the Australasian Neuroscience Society in Sydney this week. "You wouldn't think he is blind," Iñaki Carril Mundiñano, a neuroscientist on the team, told New Scientist. "He navigates his way around without any problems and plays soccer and video games."

A man receives an eye exam in Virginia. Joshua Roberts/Reuters

This is not the only case of a person with a damaged visual cortex being able to "see" on some level. But it is reportedly the first known case of a person with no visual cortex having a conscious experience of vision that is very near normal. The only problem the researchers found with BI's vision was that he's a bit near sighted.

The researchers speculate that BI is able to see because he lost his visual cortex within the first two weeks of his life. He had a condition called medium-chain acyl-Co-A dehydrogenase (MCAD) deficiency that should have meant he was unable to see. According to New Scientist, the team found evidence that other parts of BI's brain are compensating for the part he's missing.

It is just one of many examples that highlight how complicated human perception actually is. There are examples of people who are technically blind being able to carry out tasks that they're unconsciously using vision to complete, a phenomenon called "blindsight," according to neuroscientist Daniel Glaser.

The late British neurologist Oliver Sacks famously wrote about a man who was able to see, but whose brain processed visual information incorrectly, meaning that he tried to take grab his wife's head and put it on, thinking it was his hat. The anecdote became the title of Sacks's book, The Man Who Mistook His Wife for a Hat.

Sacks also wrote about a man named Virgil, who was blind from age six to 56. Once he had surgery to remove his cataracts, he had trouble telling letters apart, and wasn't able to distinguish things by sight the way he could by touch.

A relatively common visual impairment can happen when people sustain brain damage; sometimes people experience phenomena like hemineglect, in which they're unable to process the things in half of their visual field.

Other investigations into the complexities of vision will continue. All this to say, there's a lot more to vision than meets the eyeball.