Box of delight

The human eye can physically perceive millions of colours. But we don’t all recognise these colours in the same way.

Some people can’t see differences in colours – so called colour blindness – due to a defect or absence of the cells in the retina that are sensitive to high levels of light: the cones. But the distribution and density of these cells also varies across people with “normal vision” causing us all to experience the same colour in slightly different ways.