Smartphones, tablets and e-readers need 'bed mode', experts say

Blue and green lights emitted from the devices delay the prodcution of sleep-inducing hormones

Using devices at night-time that give out rays of blue light make it harder for us to get to sleep. (Rex Features)

Smartphones, tablets and e-readers need to be built with a “bed mode” in order to help users get to sleep quicker, experts have said.

New devices are being built with bigger, "bluer and brighter" screens which impact the body's ability to produce sleep-inducing hormones, according to a team of researchers.

Previous studies have shown that blue light hinders people from sleeping by suspending the on-set of their natural body clocks.

But Professor Paul Gringas, from Evelina Children’s Hospital in London, said his team found the problem was getting worse, and it was time for manufacturers to take responsibility.

Screens produce a bright light which can stop the body producing melatonin – the sleep hormone – which is produced naturally as the evening becomes darker.

Blue and green wavelengths of light affect the production of melatonin the most, as well as raising alertness in people at a time when they should be feeling sleepier.

Professor Gringas noted in the research findings, published in Frontiers in Public Health, that newer models of phones and tablets are “bluer”. These include the iPad Air, the Kindle Paperweight 1st generation and the iPhone 5s.

He went on to say: “Hardware should shift blue and green light emissions to yellow and red as we as reduce backlight/ light intensity”.

There are apps that are designed to be “sleep-aware”, where the creators have specifically aimed to decrease the blue lights, but this has not before been rolled out to whole devices.