Are you that person who snuggles into bed with your iPhone to have one final check of Facebook, or to Google that thing you’ve been thinking about all day? Maybe you use your phone to set your alarm and plug it in to charge on your bedside table? Yeah, me too. These things may be convenient, and give you a short-term boost of satisfaction, but research suggests that using your phone – or any back-lit device – before you close your eyes, will cause you to have a bad night’s sleep.
This is because the “blue” light emitted by our iPhones, iPads and laptops upsets our circadian rhythm. In the natural world, light is mostly blue in the mornings, which tells our bodies to wake up and embrace the day, whereas evening light is mostly red and green, allowing our minds to shut down and rest for the night. So by flooding your eyes with blue light at night, you’re actually triggering your brain to be alert when you should be encouraging it to switch off. Blue light also suppresses the body’s normal nighttime release of melatonin – the hormone that regulates our sleep – and not having enough melatonin confuses our body clocks even more. This means it’s harder for us to drop off and we’re more likely to have a disrupted night’s sleep. And if you fall into a bad nightly habit, then it could mess up your circadian rhythm long-term, causing more serious health problems than just feeling tired.
The advice is that you should stop using these devices at least 30 minutes before you turn in. (Kindles are ok, because they’re not back-lit and therefore don’t emit blue light.) But if you absolutely must stay plugged in until you close your eyes, there are a couple of options that might help. One is to install F.lux – a programme that automatically warms up your screen display (and therefore reduces the amount of blue light it emits) as the light of the day fades. The other, if you’re not averse to looking like a bit of a geek, is to wear glasses with orange lenses that block the blue light from reaching your eyes.
There’s also research that suggests we’re having less sex compared to a decade ago, perhaps because we’re more interested in cuddling up to our electronic devices than our partners. So, if the promise of a good night’s sleep isn’t tempting enough, then that’s another compelling reason to banish tech from the bedroom for good!
Here’s a study about the effect on our sleep of using electronic devices before bedtime by Mariana Figueiro of the Lighting Research Centre in upstate New York.
Here’s an interesting piece about the effect of light on our health from Intelligent Life magazine.