In a recent article from the BBC,
Prof Paul Gringras from Evelina Children's Hospital in London 
said "Smartphones, tablets and e-readers should have an automatic
"bedtime mode" that stops them from disrupting

man and woman tech

 The doctor said, every new model is "bluer and
brighter" and manufacturers need to show more "responsibility". As
it gets darker in the evening, the body starts to produce the sleep
hormone melatonin - which helps people nod off. Certain wavelengths
of light, those at the blue-green end of the spectrum, can disrupt
the system.

 Gringras was part of a study that was published
in Frontiers in Public Health, analysing the light emitted by
devices. In the study, it concluded there was a clear trend for new
devices to be bigger, brighter and emit more blue light. 

 Prof Gringras said, "There is converging data
to say if you are in front of one of those devices at night-time it
could prevent you falling asleep by an extra hour". There are some
sleep devices that have been designed to reduce blue-green light
emissions. A bedtime mode could filter out the blue

 For more information on how to get a great
night's sleep, visit our Sleep Matters page.