Human eyes are fine-tuned to spot facial colour changes

Our ability to spot social signals may have changed the way we see colour, new research has found. The light receptors in our eyes are well-adapted to spot key social colour-changes, such as a blushing or angry face. These emotions can change facial blood-flow, forcing a subtle colour change that we have evolved to spot - an adaptation that allows humans to predict behaviour. The researchers found that human eyes are so good at spotting these colour changes that they can accurately read the facial mating signals of a female macaque monkey better than a digital camera. Our ability to spot social signals may have changed the way we see colour, new research has found.