It ranks among the most curious phenomena in cognitive neuroscience. A handful of people in the world have “blindsight”: they are blind, but their non-conscious brain can still sense their surroundings.

Milina Cunning, from Wishaw in Scotland, lost her sight in her 20s, and later realised she had this blindsight ability. She has been studied extensively by researchers.

“If I was to throw a ping pong ball at Milina’s head, she would probably raise her arm and duck out of the way, even before she had any awareness of it,” says Jody Culham, a scientist who has scanned Cunning’s brain.

Read more about the science behind blindsight: The strangest form of consciousness

Listen to Cunning on the BBC radio series The Digital Human in an episode about the subconscious

So what is it like to navigate the world in Milina’s shoes? Here, she describes the sensation in her own words:

“I went into hospital as sighted person. I was put into an induced coma because of all the health problems I had. And I was in the coma for 52 days. When I woke up, I saw completely black. I couldn’t see a thing. They said while I was in the coma I had a stroke which left me blind.