The Science of Blocking Blue Light Before Bedtime
Block blue light on your iPhone with this trick
The ability to wake up early in the morning rests upon two factors; sleep quantity and sleep quality.
It’s not unfair to assume that the more rest you get the easier it is to get up in the morning. The same holds true if that sleep is also good quality.
Let’s talk about the effects of blue light on sleep quantity and sleep quality.
What is blue light?
Blue light is a colour on the visible light spectrum, vibrating with short wavelengths and high energy.
About ⅓ of all light is blue light, most of which is created by the sun and plays an important role in setting the circadian rhythm (body clock) and regulating the production of melatonin.
Cool, so we know blue light plays a key role in our ability to fall asleep and stay asleep. And yet millions of people are still struggling to fall asleep at night, leading to fewer good quality hours of sleep before the alarm goes off and therefore more likely to hit that snooze button.
While blue light is important for the reasons we have mentioned already, it can also have a detrimental effect on our sleep quantity and quality if we get too much at the wrong time!
Blue light is emitted from our digital screens. Most of us are using these screens all day every day soaking up all the blue light we can get. And I know this to be true in my case, laying in bed with my phone screen a hand length away from my eyes for the final daily injection of the blue light drug.
It’s probably a good idea not to use our phone during the final few hours of the day but chances are this is unlikely (unless we actively build this habit into our evening routine).
The quick win is to simply turn off the blue light being emitted from our phones and it’s as easy as 1, 2, 3 … 4.
Go to settings
Display & Brightness
Night Shift
Slide the colour temperature to ‘More Warm’
I have mine set to shift to warmer colours between 7pm and 9am.
For the first few days it’s odd using the phone with an orange tinted screen, but now I don’t even notice it.
Another quick hack is to change the entire screen to grayscale. This also helps to reduce the screen time if you have an addiction to social media. When the screen is black and white it is boring as hell to look at, nothing seems interesting or distracting and I actually find it quite painful to look at.
You can do that here: Settings app > Accessibility > Display & Text Size > Colour Filters
If you want to go even further, get yourself a pair of blue light blocking glasses and wear these for a few hours before going to sleep.
Now, what evidence is there to say we should go to the trouble of limiting blue light exposure at night?
One study published by the American Psychological Association found that not only do blue light blocking glasses improve sleep quality and quantity, but it also improves task performance, work performance and task engagement.
“We collected data from 63 managers (519 daily observations) and found that wearing blue-light filtering glasses is an effective intervention to improve physiological (sleep), attitudinal (work engagement), and behavioral (task performance, organizational citizenship behavior, and counterproductive work behavior) outcomes.” (link)
In a randomised trial, 20 adults were given blue blocking glasses 3 hours before going to sleep for two weeks. At the end of the study, the adults wearing the blue-light blocking glasses experienced significant improvement in sleep quality and their mood also improved. (link)
There are countless more studies supporting the case of blocking blue-light a few hours before bedtime and this can even help improve sleep disorders like insomnia.
I’ve always had an issue with falling asleep.
Even if I feel tired I can lay there for 2 hours before eventually falling asleep.
I just assumed I was just ‘one of those people’.
However, I am a big reader and I’ll always try and read for an hour before going to sleep and my device of choice is … you guessed it, my phone!
I read books on my phone absorbing all those blue-light waves directly into my retina for the final hour of the day.
This affected my circadian rhythm and limited the production of melatonin. I was then asking my brain and body to shut down and fall asleep with every physiological lever working against it.
I have since switched to a kindle device, scheduled blue-light to switch to warm light after 7pm and I have been falling asleep much quicker.
I’m waking up around my usual alarm time as my body clock is tuned in to waking up around 7am and then I’m trying to get some sunlight in my eyes before 8am.
It’s f’ing freezing in the UK right now but I’m grabbing my coffee and standing in the garden for 10 mins to get natural blue-light into my eyes to set my body clock for the rest of the day, knowing that this small action in the morning is helping me to get more good quality sleep and helping me beat my snooze button addiction.