Milena Canning lost her vision nearly two decades ago after a respiratory infection and a series of strokes. The 48-year-old Scottish woman emerged from an eight-week coma and couldn't see a thing. But a few months later, she was surprised to see a sparkly gift bag that flashed like lightning.

Gradually, Canning started to become aware of other moving things.

"She can see rainwater running down a window but cannot see through it," her Glasgow ophthalmologist Gordon Dutton wrote in a 2003 paper. "When her daughter is walking away from her, she can see the pony tail moving from side to side but cannot see her daughter. She can see the movement of the water going down the plug hole but she cannot see her child in the bath."

Dutton referred her to specialists at the Brain and Mind Institute in London, Canada, where she underwent tests including a functional MRI to examine the structure and workings of her brain.

The research team found Canning has a rare phenomenon called Riddoch syndrome, in which someone who is blind can see things if they are moving.

"She is missing a piece of brain tissue about the size of an apple at the back of her brain – almost her entire occipital lobes, which process vision," says neuropsychologist Jody Culham, who led the research. The study is published in the journal Neuropsychologia.

"In Milena’s case, we think the 'super-highway' for the visual system reached a dead end. But rather than shutting down her whole visual system, she developed some 'back roads' that could bypass the superhighway to bring some vision – especially motion – to other parts of the brain."

Culham explains more in the video below.

If the road is blocked, the brain takes a detour

Culham says Canning's brain is taking unplanned, unusual detours around damaged pathways in the brain.

For the study, researchers rolled balls towards Canning and she was able to not only recognize the motion, but she was able to describe the direction, size and speed of the balls. She could also grab them as they came toward her. Canning could also successfully navigate around chairs.

She was not able to identify colors and was successful about half the time at identifying whether someone's hand was showing thumbs up or thumbs down in front of her.

The research shows how resilient the human brain can be after a serious injury, finding a way to work around damage. The researchers point out that it suggests conventional definitions of "sight" and "blindness" may not be as clear as previously thought.

Canning says the research has helped her understand her unusual perception and how her brain keeps changing.

"I can’t see like normal people see or like I used to see," she says. "The things I’m seeing are really strange. There is something happening and my brain is trying to rewire itself or trying different pathways."

Mary Jo DiLonardo covers a wide range of topics focused on nature, health, science and anything that helps make the world a better place.

Blind woman can only see things if they move
Woman with Riddoch's syndrome can't see anything unless it moves.