A simple test can reveal whether someone unknowingly lives with a hidden disability known as aphantasia – a condition that leaves people unable to form mental images in their mind.
Often undiagnosed and poorly understood, aphantasia affects the brain’s ability to visualise pictures, scenes or faces, even though eyesight itself is completely normal.
Although estimates suggest between two and five per cent of people have aphantasia, the vast majority are never formally diagnosed.
Because the condition is invisible and not routinely tested for, experts believe millions are unaware they have it and only discover it later in life by chance.
…Both groups – 42 people without aphantasia and 18 who reported having it – showed a normal pupil response when actually viewing the images, demonstrating that their eyes and visual pathways were functioning normally.
However, when both groups were then asked to visualise the same light and dark shapes in their mind, a clear difference emerged.
Participants without aphantasia showed the expected pupil response, with their pupils changing size depending on whether they were imagining light or dark objects.
By contrast, the pupils of those with aphantasia did not change at all when they attempted to visualise the images.
While visual aphantasia is the most common form, researchers say the condition can also affect the ability to imagine sounds, touch, smells, tastes and movement.
Simple test reveals if you are one of the millions who suffer hidden disability aphantasia
American Buddhist Net 