Why Blue Light From Your Electronics Is Bad For You And What You Can Do About It | Sleep Clinic Services

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Why Blue Light From Your Electronics Is Bad For You And What You Can Do About It

How And Why Blue Light From Your Electronic Devices Is Bad For You and Your Sleep Health

If you’re like most people there’s nothing better than relaxing after a long day in front of the television. Or you might indulge in an e-book, scroll through your Facebook or Pinterest feed and before you know it it’s well past your usual bedtime.

But what you might not know is that the blue light coming from your electronics and gadgets could be doing serious harm to your health by affecting your sleep. And it’s not only the blue light from your smartphone, devices or TV but also the blue light from some energy efficient light bulbs that are bad for sleep health.

You see, exposure to blue light suppresses the secretion of melatonin, the sleep hormone that your body releases so you sleep. The biggest source of blue light is sunlight, but it's also found in most LED-based devices. Blue light boosts alertness and regulates your internal body clock or circadian rhythm, that tells your body when to sleep.

blue light affects sleepHow Blue Light Affects Your Sleep

In a nutshell, while you’re busily scrolling through your smartphone or binge-watching the latest season of your favourite TV show, your body thinks the sun’s still up. 

So, there’s no way it’s going to release any melatonin to help you sleep. And it’s not just watching TV that affects your body’s ability to release melatonin. We’re all really fond of curling up in bed with a good book. And while reading may help you fall asleep, how quickly you doze off depends on if you’re reading an e-book or a paper book.

A study published in the Proceedings of the National Academy of Sciences journal looked at the effects of reading on a light-emitting device compared with reading a printed book. The study found that people who read on light-emitting devices took longer to fall asleep, had less REM sleep (that’s the sleep phase when you dream) and had higher alertness before bedtime (compared to those people who read printed books).

Not only that but the study also revealed that after eight hours of sleeping, those who read on the light-emitting device were sleepier and took longer to wake up.

If you’re thinking that a little bit of screen time before bed isn’t that big of a deal. Or that it doesn’t matter if you don’t get a full night’s sleep. Think again. In the recent boom of medical research about sleep, more and more studies show that lack of sleep may contribute to the causation of cancer, diabetes, heart disease, and obesity.

But rest assured, it’s all in your control.

Here are some tips for reducing your exposure to blue light at night:

Tips on how to reduce the exposure to blue light at night 

  • When it comes to lighting in your bedroom, try using dim red lights. Red light has the least power to alter your circadian rhythm and suppress melatonin.
  • Don’t use devices, smartphones, electronics, gadgets or watch TV for two to three hours before bedtime.
  • If you absolutely must use technology that emits blue light, invest in blue-blocking glasses. Or you could install an app on your smartphone that filters the blue wavelength at night.
  • Expose yourself to sunlight. Lots of bright light during the day is good for your circadian rhythm. It can also help you to sleep at night.



Chang, A., Aeschbach, D., Duffy, J. F., Czeisler, C. A., Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness, PNAS January 27, 2015. 112 (4) 1232-1237.


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