New research has called on millennial students to block out sleep-disturbing blue light from phones, computers and tablets to improve their chances of exam success.
Light from the screens can stop the release of sleep-inducing melatonin, massively affecting the body clock.
Previous research has shown students who use a computer the hour before bedtime are three times more likely to get less than five hours sleep.
This can leave them unable to concentrate, and dull their ability to focus or do university work. The study found those who use screens before bed take an extra half an hour to get to sleep.
Now scientists from Amsterdam University Medical Centre have found wearing shades in bed stops the problem entirely.
Dr Dirk Jan Stenvers said: “Adolescents increasingly spend more time on devices with screens, and sleep complaints are frequent in this age group.
“Here we show very simply that these sleep complaints can be easily reversed by minimising evening screen use or exposure to blue light.Based on our data, it is likely that adolescent sleep complaints and delayed sleep onset are at least partly mediated by blue light from screens.”
They found blocking the light reduced the impact on the sleepy students, getting them to sleep within 20 minutes.
Dr Stenvers added: “Sleep disturbances start with minor symptoms of tiredness and poor concentration but in the long term we know that sleep loss is associated with increased risk of obesity, diabetes and heart disease.”