The Colour That Stops You Sleeping Properly

The ‘melanopic display’ is able to reduce or increase the colour.

The ‘melanopic display’ is able to reduce or increase the colour.

Cyan — the greenish-blue colour that smartphones and other devices emit — could stop people sleeping properly.

People exposed to screens which emit less cyan felt more sleepy and had higher levels of the ‘sleep hormone’ melatonin in their system, new research finds.

However, those exposed to more cyan felt more awake and had lower levels of melatonin in their system.

The researchers developed a new type of visual display for their tests.

The ‘melanopic display’ is able to reduce or increase the amount of cyan, while keeping colours true.

Here are some different types of cyan:

Professor Rob Lucas, study co-author, said:

“This outcome is exciting because it tells us that regulating exposure to cyan light can influence how sleepy we feel.

Our study also shows how we can use that knowledge to improve the design of visual displays.

We built our melanopic display by adapting a data projector, but we would expect that this design could be applied to any type of display.

Such displays could, for example, help phone obsessed teenagers to fall asleep, or support alertness in people who need to use a computer at night.”

For the study, people watched a movie either with or without cyan.

Both movies looked the same as the technology balances out the other colours.

Melatonin levels were tested from saliva samples and people were asked how sleepy they felt afterwards.

Dr Annette Allen, the study’s first author, said:

“The new display design could actually have a wider benefit, as it seems that this technology also improves image appearance.

Like adding salt to food, we aren’t necessarily aware that it’s been done though we appreciate the effect.

Exploiting metamerism to regulate the impact of a visual display on alertness and melatonin suppression independent of visual appearance”

The study was published in the journal Sleep (Allen et al., 2018).

Author: Dr Jeremy Dean

Psychologist, Jeremy Dean, PhD is the founder and author of PsyBlog. He holds a doctorate in psychology from University College London and two other advanced degrees in psychology. He has been writing about scientific research on PsyBlog since 2004.

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