man on the computer at night man on the computer at night What is this guy doing wrong? (Photo: chaoss / Shutterstock)

You can use screens at night – and sleep better – if you follow this tip

Screens themselves aren't so bad. Blue light is the real problem, a new study says.

It's pretty common medical advice to stay off screens before bed. That can be hard in a technological, 24/7 age such as this. Luckily, scientists from Israel's University of Haifa and Tel Aviv Assuta Hospital have confirmed that screens themselves aren't the problem. The blue light they emit is the real culprit.

Scientists have long known that light, particularly blue light, impairs sleep, but nobody was quite sure whether the amount of light or type of light was a bigger deal.

The scientists had participants look at computer screens from 9 p.m. to 11 p.m. They gave one group screens that emitted strong blue light, another weak blue light, another strong red light and another – you guessed it – weak red light.

red light and blue lightRed light is made up of shorter wavelengths than blue light, making it less intense. (Photo: Sasa Prudkov/Shutterstock)

The participants then went to sleep, and the scientists measured various aspects of their sleep, including quantity of sleep, interruptions (how many times the sleepers woke up) and body temperature throughout the night. The next day, the scientists also had participants fill out questionnaires.

As it turned out, how intense the light was had some effect on sleep. But the color of the light mattered way more. The participants who got red light slept much more soundly than the ones who got blue light. And you know what they say about disturbed sleep: it's just as bad as no sleep. Ultimately, if you want to be an A+ sleeper, you should still avoid screens. But you can still snag a solid A- by just avoiding blue light.

"Exposure to screens during the day in general, and at night in particular, is an integral part of our technologically advanced world and will only become more intense in the future,” explained Professor Abraham Haim, who ran the study. “However, our study shows that it is not the screens themselves that damage our biological clock, and therefore our sleep, but the short-wave blue light that they emit. Fortunately various applications are available that filter the problematic blue light on the spectrum and replace it with weak red light, thereby reducing the damage to the suppression of melatonin.”

So don't stress too much about using screens before bed. Just make sure you're using a program that replaces blue light with red light at night, like f.lux or one of the bazillion other free programs that do just that.


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You can use screens at night – and sleep better – if you follow this tip
A new study says you can keep using screens without losing sleep, as long as you avoid blue light.