Smartphones and electronic devices should come with a special "bedtime mode" to help people sleep better, a health expert has urged.
Professor Paul Gringas from Evelina Children’s Hospital in London said devices are being manufactured with brighter and far bluer screens - and it's having a detrimental affect on sleep.
He suggests manufacturers introduce a "bedtime mode" (similar to flight mode) which would switch the blue and green light emissions to yellow and red.
It would also reduce backlight/light intensity.
In the past, studies have linked blue light from device screens with reduced levels of the sleep-inducing hormone melatonin.
Gringas' research, published in Frontiers in Public Health, found new device models such as the iPad Air, Kindle Paperwhite 1st generation and iPhone 5s feature "bluer" screens.
He writes: "There needs to be the recognition that at night-time 'brighter and bluer' is not synonymous with 'better'.
"Ideally future software design could be better optimised when night-time use is anticipated, and hardware should allow an automatic 'bedtime mode' that shifts blue and green light emissions to yellow and red as well as reduce backlight/light intensity."
Previous research also suggests checking a screen with blue light before bed can reduce how alert a person is the following day.
A study from Brigham and Women's Hospital in Boston, Massachusetts found lack of sleep (caused by blue screen time) led to people feeling tired and zombie-like the next day.
"We know from previous work that light from screens in the evening alters sleepiness and alertness, and suppresses melatonin levels," Dr Anne-Marie Chang, an associate neuroscientist in BWH’s Division of Sleep and Circadian Disorders told The Huffington Post.
"This study shows comprehensive results of a direct comparison between reading with a light-emitting device and reading a printed book and the consequences on sleep."
Sleep deficiency has also been linked to health problems such as obesity, diabetes, and cardiovascular disease.
Chronic suppression of melatonin has also been associated with increased risk of certain cancers, added Dr Chang.
