Why you really need to stop looking at your phone before bed

Samsung Galaxy S6 Edge
Looking at your phone exposes you to blue light which can damage your sleep and health.

We’ve all done it. Most of us probably still do it. That final look at our mobiles before bed, just to see if there were any last minute notifications, which turns into mindless scrolling through updates on Instagram or Twitter or Facebook, until you realise it’s 2am, you’re totally wired, and you need to be up in four hours for work.

Ok, maybe it’s not that bad every night. But a lot of us are guilty of using our smartphones right before we try to go to sleep. And then we wonder why we tossed and turned all night, struggling to get some shut eye, before waking up feeling like we had zero hours sleep, totally drained of energy.

Take it from us: you need to stop looking at your phone before bed. Actually, don’t even take it from us. Take it from science. Because here’s what actually happens to you if you don’t give yourself an hour’s break from screen time before going to sleep.

What is blue light?

You can find LEDs which produce blue light in your devices, such as your smartphone or tablet. The wavelengths produced by blue light are very short, which make things much clearer, hence why it’s used for our display screens. The sun is a giant natural source of blue light. But we use LEDs to produce artificial blue light for our own purposes.

How blue light affects us

Scientific studies show that exposure to blue light during the day can increase cognitive performance and alertness. This is fine during the day. But this is terrible when you want to go to sleep.

Exposure to blue light disrupts your “circadian rhythm”, or biological clock. By staring at your phone before bedtime, you’re messing with your natural impulse to want to sleep at the right time in the evening. You’re essentially giving yourself a massive dose of sunlight, tricking your body into thinking it’s daytime and heightening your alertness.

And that’s why it’s hard for you to get a decent night’s sleep if you checked your phone before bed.

This is the alarming conclusion of a 2014 study into the effects of blue light on sleep published in the scientific journal PNAS:

“The use of light-emitting electronic devices for reading, communication, and entertainment has greatly increased recently. We found that the use of these devices before bedtime prolongs the time it takes to fall asleep, delays the circadian clock, suppresses levels of the sleep-promoting hormone melatonin, reduces the amount and delays the timing of REM sleep, and reduces alertness the following morning. Use of light-emitting devices immediately before bedtime also increases alertness at that time, which may lead users to delay bedtime at home. Overall, we found that the use of portable light-emitting devices immediately before bedtime has biological effects that may perpetuate sleep deficiency and disrupt circadian rhythms, both of which can have adverse impacts on performance, health, and safety.”

Sleep deprivation is serious. We need rest to recover.

According to the NHS: “Regular poor sleep puts you at risk of serious medical conditions, including obesity, heart disease and diabetes – and it shortens your life expectancy.

What’s more, a lack of sleep can hurt your mental health: “Given that a single sleepless night can make you irritable and moody the following day, it’s not surprising that chronic sleep debt may lead to long-term mood disorders like depression and anxiety.

“When people with anxiety or depression were surveyed to calculate their sleeping habits, it turned out that most of them slept for less than six hours a night.”

How to sleep better

There’s only one tip you really need and that’s this: turn off all your screens and devices a full hour before you go to bed. Give yourself proper time to wind down without any blue light. Take a bath, read a book or magazine, chat with your partner. Anything but staring at blue light. You’ll be surprised by how much better you sleep if you do this.