Revealed: How humans see different colours in different seasons

Washington DC: Revealing that humans see things differently in winter compared with summer scientist are now sheding light on human's ability to process colours.

Researchers from the University of York have examined how human's colour perception changes between seasons and in particular how they process the colour known as unique yellow.

Scientists claim that humans identify four unique hues blue, green, yellow and red that do not appear to contain mixtures of other colours.

Unique yellow is particularly interesting to scientists as it is stable across large populations everyone agrees what unique yellow looks like despite the fact that people's eyes are often very different.

Author Lauren Welbourne said that what they are finding is that between seasons Human's vision adapts to changes in environment, so in summer when there is a much larger amount of foliage, their visual system has to account for the fact that on average they are exposed to far more green.

The researchers tested 67 men and women in January and June. Participants were placed in a darkened room, allowed to adjust to the light and then on a machine called a colorimeter asked to adjust a dial backwards and forwards until they felt that they have reached the point where it had reached unique yellow with no hint of a green or red.

Welbourne said that although no disorder can fixed by this, the more they learn about how vision and colour in particular is processed, the better they can understand exactly how humans see the world.

He added that this process is very useful because one can adapt to these huge seasonal changes in environmental colour and continue to see and discriminate between colours accurately.

The research is published in the Journal Current Biology.