Do Phones & Tablets Really Keep Us Awake?

A UK survey in 2014 revealed most of us use electronic devices before we fall asleep. The survey revealed 78% of adults, rising to 91% for 18-24 year olds would use their phones or tablets before bed.

The professor who conducted the survey explains that “Blue light from these devices suppresses the production of the sleep-inducing hormone melatonin”. So the screens are in fact chemically altering our brain which makes falling asleep more difficult.

As well as suppressing the production of melatonin, according to one Optician the blue violet light is also potentially hazardous and toxic to the back of your eyes – causing eye fatigue, dryness and over a long period of time can be potentially damaging for your eyes.

What is Blue light?

Being exposed to artificial light at night, on a basic evolutionary level interrupts our circadian rhythm – the physical and mental cycle our bodies go through on a roughly 24-hour cycle. Light has a big effect on this rhythm, for example we are used to seeing orange at dawn and dusk. This is why if you take a long-haul flight the cabin lights try to help your circadian rhythm adjust to minimise jet lag.

What is so special about ‘blue light’? Only since 2001 have scientists discovered that light in the blue wavelength of the light spectrum – specifically in the 400-500 nanometer range which is described as high-energy visible (HEV) light – can have a physiological impact and disrupt your production of melatonin.

Because blue light is so bright, it’s ideal for LED devices like your phones, tablets, monitors, laptops and TVs. You’re grateful for it when using your phone in broad daylight, maybe not so much last thing at night in the pitch dark.

So after millions of years of humans seeing sun rises followed by bright daylight and sun sets followed by darkness, it’s not surprising that for the past 20 years or so since we have started being exposed to this particular high-energy, bright blue light emanating from screens – it might have a impact on our health.

blue light

Other effects

As well as making it harder for you to fall asleep, there is research to suggest that exposure to blue light can damage your eyes, have an impact on your blood pressure, mood and even cause depression. Radiation from blue light, which on the light spectrum is very close to UV radiation is also considered to be a “carcinogenic pollutant” meaning it’s been linked to higher cancer rates.

I’m obviously not suggesting that browsing the web, watching YouTube videos or catching up on some Netflix on your tablet before bed is going to kill you – but it’s interesting how there is a measurable physiological impact from the light coming from our screens.


Ideally for a good night sleep you should refrain from any TV, mobile devices or even lighting in your bedroom in the couple of hours prior to going to sleep – but I doubt many of us would really want to do that.

There are apps available, like Nightly, that automatically reduce the brightness of your device at certain preset times to help reduce the impact of using them before sleep – although of course you could just lower the brightness on your phone or tablet yourself.

So dimming your phone or tablet will help, but is there any way to block out blue light specifically?

Limiting Exposure to Blue Light

You can invest in light-filtering glasses from companies like Gunnar which claim to help reduce the impact of Computer Vision Syndrome (CVS) and mitigate the problems associated with exposure to blue light from screens.

‘Low Blue Light’ monitors are also available for those who like to use their computers late into the night. Companies including Asus, BenQ and Viewsonic have dedicated monitors that feature eye-care technology to reduce the levels of blue light you’re exposed to.

blue lightIt’s not just physical glasses or monitors that can help – f.lux software available for Windows, Mac OS, Linux and even iOS devices adjusts colours on the screen to reduce the stimulating effects of blue light at night and even simulate the colours of sunrise and sunset to help match your circadian rhythm. Android users can use a similar app called Twilight.

For me, one of the best ways of helping you to fall asleep is by having orange or red light in your bedroom. LED mood lighting can be a great way to help combat the effects of blue light. I personally use a Philips LivingColors light, which you can buy for around £50, in my bedroom. I set it to a dim orange colour using the remote control and I genuinely think it helps me feel more tired. For the opposite effect, sometimes I’ll set it to a bright blue colour first thing in the morning to help me feel more awake. I’d highly recommend it.


If I were writing a correlation-implies-causation tabloid headline, the title might read: “iPhones Cause Cancer” or “Reading On A Screen Before Bed Might Be Killing You” as the Huffington Post puts it. In reality, small-scale lab tests and animal testing aside, the most obvious and common impact on the majority of us is making falling asleep more difficult.

It doesn’t affect everyone, and other variables like noise, temperature and stress will impact how you sleep. However, it’s still interesting to know that light does have a genuine effect on your body’s circadian rhythm as well as being potentially damaging to your eyes. As for sleep in particular – the blue-lights’ high-energy particles suppress our melatonin production so we simply don’t feel as tired.

If you suffer from insomnia or have trouble falling asleep, try to avoid screens and monitors late at night. Alternatively you could look into brightness reducing apps, blue-light filtering glasses and monitors or simply invest in some orange lighting for your room.

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