Blindness: Scottish woman’s “blind vision” surprises doctors

“When I woke up, everything was black.” After a coma that lasted 52 days, Milina Cunning opened her eyes without being able to use them. A cerebral attack had reached the visual cortex of this Scotswoman. But a few months later, she had the sensation of being able to see colors, she explains in a report by the bbc4, The digital human, relayed by the magazine Paris Match.

A neurologist, intrigued by his claims, decided to give him some tests. As he walked her through a corridor where chairs had been placed to impede her movement, he observed that she managed to avoid them all. A feat that would puzzle many scientists.

Scientists in the fog

It is actually a phenomenon already known, but badly described: the blindsight, or blind vision in French. Even when the part of the brain responsible for processing visual information has been damaged, especially in the event of a cerebrovascular accident (CVA) as is the case with this Scottish woman, part of the light signals continues to flow.

Several hypotheses have been put forward by neuroscientists. Some of them could go to the thalamus, which regulates reflex processes, but which would also have the ability to project the detection of shapes and movements unconsciously. Some areas of the visual cortex could also be preserved, and convey a concept of detection rather than an image of the environment.

Emergency vision

In all cases, blindsight is manifested by a kind of replacement sense based on the same tool, the eye. It goes unnoticed by sighted people, who have little need of it in their daily life, but can be expressed by people who have lost their sight, to compensate for their handicap.

“If there is an obstacle on the road or stairs, she is able to respond appropriately without even realizing how,” reports Jody Culham, a Canadian scientist who performed a brain scan of Milina Cunning. “I can’t see things, but I know they’re there,” summarizes the Scotswoman.