Neuroscientists at Johns Hopkins University say the blind and the sighted share a similarly in-depth understanding of colour.

The researchers asked both congenitally blind and sighted people the colours of a series of man-made and natural objects, such as polar bears, why they were that colour and how likely two of the same type of object were to be the same colour.

The blind participants did not always know what colour things were, but their reasoning about colour was similar to that of sighted people.