Do blue light blocking glasses actually work?

This article is another instalment of Sleep for Success - a LinkedIn series empowering you to your best nights sleep. With sleep not only important, but imperative for optimal wellbeing and peak performance alike; it's a pleasure to leverage my 14 years of academic and professional experience to share expert tips, tricks and techniques to help you sleep longer, deeper and wake more refreshed. Supercharged by sleep, look forward to achieving more, in less time, with less effort - naturally. Please share with anyone you feel will benefit, and of course, sleep well.

Blue light - the number one factor to control your circadian rhythm, melatonin and ultimately, sleep. Recognising that of all things to help you sleep better - fall asleep faster, wake less through the night, sleep deeper, wake more refreshed - nothing will make a greater difference than blocking out blue light before sleep. Even if you are not on a screen in the hours before bed, blue light isn’t just from screens - it’s all artificial lights. Ceiling lights, reading lights, ambient street light - all are potent sources of sleep suppressive blue light. In order to mitigate this impact, I recommend 100% blue light blocking glasses - and here is everything you need to know about them accordingly.

Why do blue light blocking glasses work? 

Light is our primary zeitgeber - factor to control our circadian rhythm, melatonin, and therefore, our sleep quality. In darkness, melatonin is produced - enabling us to fall asleep and stay asleep with ease. In light, melatonin is suppressed (well, delayed; but more on that later), which means we struggle to fall and stay asleep. Admittedly, other factors are involved - diet, exercise, temperature, your bedtime routine - all matter, but nothing matters as much as blue light: period.

What does the evidence say? 

There are countless studies which highlight the effectivity of blue light glasses - and in all fairness, if these studies didn’t exist, I wouldn’t be such a vehement advocate. Surmised in a 2021 meta analytic review, they reported: “Out of the 24 clinical studies focusing on sleep, there was substantial evidence for blue-blocking glasses being a successful intervention for reducing sleep latency (time taken to fall asleep) in individuals with sleep disorders, jet lag, or variable shift work schedules. 

Specifically, a 2016 study found wearing 100% blue light blocking glasses from 9pm each evening for 2 weeks helped individuals fall asleep 1 hour and 18 minutes earlier than normal. 

Similarly, another 2016 clinical trial highlighted that wearing 100% blue light blocking glasses for 2 hours before bed reduced night time wakings by 66%. 

What if my problem is sleeping lightly and waking through the night? 

Light sleepers rejoice - as noted above, wearing these glasses can help you too. As blocking out blue light enables greater melatonin production, which then helps you sleep deeper, you can look forward to more restful, rejuvenating sleep. 

I have blue light filters in my prescription lenses - but I still have sleep problems. Why?

Blue light filters in prescription lenses are great - for daytime use. As they still allow 50-60% of blue light to enter the eye (which during the day is helpful), in the evening they are going to be only half as effective as you need them to be. Rather than 40-50% blue light blocking, you need glasses that block out 100%, which typically have an orange or red lens. 

What if I don’t look at screens before bed - do I still need them? 

Avoiding screens before bed is a fantastic, and challenging, feat - so first up, well done! Screens are one of the most potent sources of blue light, so reducing your use of laptops, phones, kindles - even if the brightness is low - in the two hours before bed is helpful, without a doubt. However, as artificial light also contains blue light, unless you are in complete darkness for 2 hours before bed, you still need them. 

What if I use night mode on my screen - do I still need them? 

Night mode is a fantastic concept - but unfortunately, it’s more effective for marketing than it is for your sleep. A 2011 academic study found using night mode made as little as 4% difference in melatonin levels - and therefore, a minimal 4% impact to sleep quality by using it. Specifically, the researchers found that without night mode, melatonin was suppressed by 23%. With night mode on, melatonin was suppressed by 19%. In all fairness, with night mode on maximum strength, it suppressed melatonin by 12%; yet the researchers noted: “having the night shift at any mode is not significantly different than not using it”

Are all 100% blue light blocking glasses the same? 

Definitely not. And further, even though they may be marketed at 100% blue light blocking, it’s possible they fall short of this. When in doubt, reach out to a professional such as myself and ask - you’ll save yourself many sleepless nights by doing so. In absence of this, my recommended glasses are in my hand picked, expert curated sleep kit - so either way, your sleep is saved. Remember: of all things that will help you sleep better, this is number one - so make sure you resource up - your best nights sleep is just around the corner.