Light therapy glasses and wearables are one of the most interesting recent innovations to happen in the world of consumer sleep technology. A couple of years ago I reviewed a second-generation wearable from Pegasi.
Since that time, more and more startups have begun to produce similar products, recognising the huge potential of light therapy vast potential for improving sleep, boosting energy in the daytime, solving jet-lag and shift-work issues, and as a tool to help optimize overall health and wellbeing, productivity and performance.
This technology might be new, but light has been used as a ‘medicine’ by humans for millennia including ancient Egyptians, Romans, Greeks to name just a few.
In this article we’re focusing on just one aspect of light’s healing properties – sleep and circadian health. And we hope to shed light (sorry, terrible pun) on how this exciting, innovative new area of sleep-tech can help reduce tiredness and fatigue during the day, and help you fall asleep better at night. We hope to answer all your questions including:
- how does light therapy work?
- how can light therapy glasses improve sleep, jetlag, insomnia and night shift problems?
- what are the best light therapy wearables and glasses in 2023?
So grab a favourite beverage, crank up the Fleetwood Mac, or whatever floats your boat, this is a deep dive!
Here’s a quick summary of the leading light therapy glasses and wearables you can buy in 2023 right now.
The best light therapy wearables and glasses in 2023
|Device||Price||Recommendation||Light spectrum||Session duration||Typical battery life|
|Luminette 3||$199||Best lightbox alternative||Blue||20-30 mins||10 days|
|Ayo||$299 (save 10% see below)||Long battery, app smarts||Blue-turquoise||20-40 mins||26 days (with case)|
|Propeaq||$250||Great for sports, biohackers||Monochromatic blue||~30 mins||5 days|
|Pocket Sky||€198||Ultra-compact, app-free||Blue||~20 min||14 days (with case)|
|Re-Timer 2||$169||Clinician recommended||Green-blue||45-60 min||8 days|
|Sula Glasses||$139 (pre-order from $79)||First ever 'discreet ' LT wearable||Blue-Turquoise||30 min||7 days|
Superlative battery life, smart programs
Ayo Wearable Quick Specs
- Website: – https:goayo.com
- Light source/colour: – Blue-turquoise (peak ~470 nm)
- Session duration: – 20-40 mins
- Brightness/luminosity: 3 levels – low, medium or high (100% intensity approx. 250 µW/cm²)
- Typical battery life: 26 days (with charging case)
- Weight: 31 grams
- Bluetooth: Yes
- Wireless charging: Yes
- App features: Travel, Sleep, Energy programs and more
- Price: $299 with 60-day 100% refund policy. Exclusive 10% discount ➡️ Use coupon SG10
- Read Ayo Reviews on Amazon
The Ayo story began a few years back in the Netherlands when the 3 founders/ entrepreneurs experienced how lack of light during short, dark winter days had an effect on their energy levels.
Debuting on Kickstarter in 2015 as a ‘light-based personal energy system’, the Ayo light therapy wearable became publicly available in 2017, and has since gone on to achieve great acclaim, scooping the 2018 Red Dot Design Award in the Life Science and Medicine category.
Sporting 4 LEDs equipped with ‘light diffuser technology’, Ayo emits a blue-turquoise light with a dominant wavelength of ~470 nm (± 2nm). Ayo sessions last between 20-40 mins depending on which of the 3 variable brightness levels you select in the app. In addition, there’s an onboard ambient light sensor which adjusts the brightness of the LEDs at a rate of 0.1sec to ensure optimal light intensity.
>> Read our in-depth Ayo Review here
A neat feature is the built-in capacitive sensor which can tell if you’re wearing the device or not. So if you need to take a brief break, AYO pauses your your light therapy session program when you take it off and automatically resumes once it’s back on your head.
One of Ayo’s unique features is that it comes with a rugged shell case which double as a rechargeable power bank. It even charges wirelessly so you don’t have to mess with cables. So whereas fully charged Ayo will give you about 3 hours uses or around 6 sessions, the 500mAh battery in the case has enough capacity to give you up to another 10 hours charge, an additional 20 sessions. That works out to nearly a month’s worth of daily usage without having to recharge your device.
Ayo’s smartphone app has three main programs: Sleep, Energy and Travel depending on whether you want to boost your energy levels in the dayime, optimize your sleep/wake patterns, or cope with jetlag on a long-haul flight. Based on your own data or travel plans, the goAyo app algorithms will make an analysis and calculate a personalized program with the optimal times to wear Ayo, depending on your needs.
Based on it’s superlative battery performance, the hard shell case and its specific programs to deal with jetlag, Ayo is a great choice to consider if you’re looking for light therapy wearable you can use away from home for an extended period without needing to continually charge it.
EMF-free, instant-on version of Ayo glasses
AyoLite Wearable Quick Specs
- Website: – https:goayo.com
- Light source/colour: – Blue-turquoise (peak ~470 nm)
- Session duration: – 20 mins
- Typical battery life: 8 sessions between charges
- Weight: 31 grams
- Bluetooth: Yes
- Wireless charging: No
- App features: None
- Price: $199 with 60-day 100% refund policy. Exclusive 10% discount ➡️ Use coupon SG10
- Read Ayo Reviews on Amazon
Released in December 2020, AyoLite is, as you’ve probably already guessed, a redesigned, stripped version of the award-winning Ayo wearable. AyoLite retains pretty much an identical form factor as its more expensive cousin, the main cosmetic difference being a slightly lighter shade of blue in the folding arms.
Probe a little deeper and you’ll see the left arm also incorporates a double-pronged charging socket to be used with the included proprietary charging cable. But apart from that, AyoLite retains the same high build-quality, materials and LED light sources of the full version, only $100 cheaper.
So what’s missing from this version? Well, AyoLite was introduced in response to customer demand for a non-connected version of AYO, so AyoLite is very much designed to work with as little fuss as possible.
There’s no app to connect with your phone (although intriguingly the makers say it will be supported by a new app version soon), which means you lose the ability to set custom programs for Sleep, Energy, Travel, you also lose the ability to change the brightness setting, and most obviously, AyoLite doesn’t include the same hard shell case which doubles as a wireless charging dock.
>> Check out our in-depth Ayo Review here
Instead AyoLite’s design ethos is much more similar to Pocket Sky in that there are no buttons, no options to fiddle with, all you do is open the arms, and the device switches on automatically and then switches off again after 20 minutes.
AyoLite holds up to 8 sessions on a single charge, meaning you’ll only have to charge once a week, assuming daily usage. For travel and storage you get a simple, protective travel case, which means AyoLite needs to be charged with the supplied cable.
All in all, AyoLite keeps the award-winning design of its predecessor, and strips back the smart functionality into a device you can just pick up and start using immediately
Take 10% off AyoLite NowUSE COUPON 'SG10')
Propeaq Premium Light Glasses
Perfect for optimising performance, productivity and biohacking
Propeaq Premium Light Glasses Quick Specs
- Website: – https://www.propeaq.com/
- Light source/colour: – monochromatic blue light 468 nm
- Session duration: – 15-30 mins
- Brightness/luminosity: ~ 35-40 lux
- Weight: 41 grams
- Typical battery life: 5 days
- Wireless charging: No
- Bluetooth: Yes
- App features: Jetlag, shiftwork apps available
- Price: €199 (Euros) with 30-day money-back guarantee
Next up we have Propeaq (pronounced ‘pro-peek’ if you weren’t sure) Premium Light Glasses. CEO and founder of the company, Toine Schoutens has a background in healthcare, and also worked closely with Philips, jointly developing some of the first ever light therapy devices in the medical sector and helping to usher in the first ever consumer wake-up light in 2006.
Realising that ‘“sitting in front of a light box every day in not an efficient use of your valuable time,” Netherlands-based Schoutens and his team set about designing the ultimate portable light therapy system, which resulted in the Propeaq Premium Light Glasses.
Propeaq looks just like a standard – if not slightly larger than average – pair of sporty sunglasses. But lurking underneath the slick design is a heap of carefully considered, innovative technology. Integrated inside the frames is are two LED light strips located just above your eyes. Interestingly, instead of using tuned, full spectrum white light, Propeaq’s LEDs are monochromatic, emitting only blue light at a wavelength of 468 nm.
Blue-wavelength light has the most effect on suppressing the production of melatonin, hence Propeaq’s LEDs are able to operate at an overall lower light intensity than other wearables, because they only need to shine in the blue part of the light spectrum.
In an email, Schoutens told me this means that Propeaq approximates a luminosity equivalent to only 35 – 40 lux at eye-level, which is about the same as a 600 lux blue light box at 30 cm, which in turn is about the equivalent of a 10.000 lux polychromatic (full spectrum) white light box at a distance of 30 cm.
Also we have the interchangeable coloured lenses. Propeaq glasses come with swappable light-blue and amber lenses. The idea is that when you’re using the built-in active LED light you use the light blue lenses to simulate as much as possible morning sunlight.
The amber lenses by contrast are for night-time, and you’d use them as you would use a normal pair of blue-blocking glasses. This means that if you’re trying to use light therapy to adapt your body clock to a new timezone, or an unusual shift-working pattern, you don’t have to carry around a separate pair of blue blockers with you.
Another application for Propeaq is in sports and performance. Because Schoutens has more than 15 years of guiding top athletes on the world stage, Propeaq technology has been used by hundreds of professional sports people including Formula One drivers, swimmers, cyclists, and Olympic delegations to ensure peak performance no matter what timezone, or time of day they have to compete in.
Finally, Propeaq comes with a smartphone app with programs for shiftwork and jetlag giving you guidance for when to use the active blue light component and when to swap to the amber lenses.
If you’re looking for a stylish light therapy wearable you can wear in public, whether you’re at work, in the gym, travelling or just walking about, Propeaq’s sunglass-like design, is unobtrusive and perfect for optimising your sleep, energy and body clock, whether you’re a professional athlete, biohacker, or just someone who want to ensure optimal circadian health.
Ultra-compact, minimalist and design-focussed
Pocket Sky Quick Specs
- Website: – https://www.pocket-sky.com/
- Light source/colour: – Blue-enriched white light (peak 470 nm)
- Session duration: – 20mins
- Brightness/luminosity: 500 lux (equivalent to 8000 lux light box)
- Weight: 12 grams
- Typical battery life: 14 days with charging case
- Wireless charging: Yes
- Bluetooth: No
- App features: None
- Price: €198 (worldwide shipping coming Sep 2020)
Unveiled at CES 2019 in Las Vegas and launched 6 months later via Kickstarter and Indiegogo-Indemand, Pocket Sky is an extremely compact and lightweight light therapy wearable for enhancing your energy, mood, sleep and overall well-being.
Gaining a Red Dot Design award in 2019 Pocket Sky stands out from its competitors by boasting a minimalistic aesthetic, and an ergonomic approach that’s laser focussed on practicality and ease of use. Hailing from Austria, the two founders of Pocket Sky, industrial designer Mark Wallerberger and electrical engineer Michael Geyer hold several patents for in the field of wearables and have a long history of developing sophisticated wearable products including glasses, headwear and shoes.
>> Read our in-depth Pocket Sky review here
By some kind of voodoo design magic, the inventors have managed to shrink the form factor so that Pocket Sky into a minuscule 12 grams, weighing less than a single compact disk. More surprising is that sitting atop the frame is an array of 56 full spectrum LED lights which emit blue-enriched light at a peak wavelength of around 470 nm. The makers say Pocket Sky produces around 500 lux at eye level, equivalent to an 8000 lux SAD therapy light box.
As part of the zen-like design ethos, the makers have tried to remove as many obstacles from using Pocket Sky as possible. This may be a downside for some folks – for example, there’s no smartphone app.
But on the flipside, removing options and endless tweakability, means the device will no appeal to those who lean towards form, simplicity and practicality, and don’t want to tethered to their phones all the time. Another benefit of being an app-free product is that Pocket Sky is Bluetooth-free, a boon for those who are concerned about EMF’s and their potential affects on health.
The minimalism even extends to powering up the device, there’s not even an on/off button! Instead, the glasses are automatically activated when you remove them from the included case, which doubles as a wireless recharging unit. The case connects with USB-C but left unplugged, you’re good for 14-days use (twice a day) before you have to recharge.
Once activated, Pocket Sky stays on for 20 minutes before switching itself off. Despite the lack of customisation or app functionality, the makers recommend Pocket Sky for a range of uses; enhancing productivity in the workplace, battling with shift-work schedules, jet-lag and beating the winter blues.
Pocket Sky is very much a hardware-oriented, tactile user experience – there’s no data collection, no smart programs, no personalisation, but by extension, no fiddling around with your smartphone. It’s very much a user-centric product, designed beautifully to do one thing very well.
Science-based green light wearable
Re-Timer 2 Quick Specs
- Website: – https://www.re-timer.com/
- Light source/colour: – Green-blue light (peak 500 nm)
- Session duration: – 45-60 mins
- Brightness/luminosity: Low = 315 lux, High = 506 Lux
- Weight: 75 grams
- Typical battery life: 8 days
- Wireless Charging: No
- Bluetooth: No
- App features: None (jetlag/shift-work calculators available on website)
- Price: $189 with 60-day money back guarantee
- Read Re-Timer Amazon Reviews
Next, in the spirit of Monty Python ….. something completely different. Winning the award by a long stretch for the most wacky styling, Re-Timer is a light therapy wearable that eschews snazzy looks in favour of scientific rigour, led by Dr Helen Wright, and Professor Leon Lack, world-renowned sleep researchers who have been studying and treating sleep problems for over 4 decades.
The academics had been working on a prototype light therapy device since 2000. 10 years later they formed the company Re-Time Pty Ltd, to bring a commercial product to market. With a team of 7 engineers, 4 design iterations and nearly 2000 hours of CAD design alone, they released the original Re-Timer in 2013. Now in its second generation, Re-Timer 2’s unique design features are the result of extensive R&D which has subsequently been backed up by an impressive list of peer-reviewed studies and clinical trials which the company lists on its website.
It’s not only the ‘alien scuba-mask’ looks that make this wearable a little different to its peers. For a start, Re-Timer uses greenish-blue light, at a peak wavelength of 500nm, instead of the more commonly used 468-470 nm. In an FAQ page on their website, the company states that Re-Timer chose to ‘go green’ because “this balances the safety concerns of blue light with the efficacy of the shorter blue and green wavelengths. We have completed extensive product testing on both optical safety and efficacy.”
Also, Re-Timer shines the light from the bottom of the eye because in tests, the inventors found it avoided blockage by the eyelashes and allows normal activities to be carried out more easily when you’re using the device.
Re-Timer 2 has two brightness settings, high (506 lux) and low (315 lux) according to the user’s specific and time. For example, if you suffer from a mid-afternoon slump, and want to overcome sleepiness and get an energy boost, you can wear the glasses at low brightness for 15 minutes to get the intended benefit.
Re-Timer is definitely the most quirky looking out of all the bunch, but it’s also, along with Luminette, a wearable that’s recommended by sleep physicians and boasts hard, scientific evidence to prove its efficacy.
The orignal light box alternative
Get 10% Off Luminette 3USE 'SLEEPGADGET'
Luminette 3 Quick Specs
- Website: – https://www.myluminette.com/
- Light source/colour: – Blue-enriched white light (peak 468/ 570 nm)
- Session duration: – 20-45 mins
- Brightness/luminosity: 3 levels – 500, 1000 or 1500 lux
- Typical battery life: 10 days
- Weight: 50 grams
- Wireless charging: No
- Bluetooth: Yes
- App features: basic
- Price: $199 with 30 days money back guarantee
First off the bat we have Luminette 3, the third-generation light therapy wearable from Belgian health-tech outfit Lucimed. Luminette comes with a long and solid pedigree. Developed after 4 years of research at the University of Liege, the Gen 1 device was the very first light therapy wearable to hit the market, way back in 2006.
Since that time, they’ve progressively tweaked and refined the product, carried out an impressive body of scientific research, and managing to shift over 80,000 light therapy devices.
Whilst Luminette may not be the most stylish wearable in our selection, it was designed from the ground up to give all of the benefits of a standalone light box in a wearable form factor. And indeed, an independent trial found that Luminette had comparable beneficial effects to a 10,000 lux Philips Energy Light SAD lamp.
>> Read our in-depth Luminette 3 review here
Luminette’s patented optical system is designed to mimic how sunlight hits your eyes, so rather than shine light directly into your retina, eight blue-enriched white LEDs project light forward onto a ‘hologram’ – essentially a mirror array, which then scatters and reflects light back into your eyes. This stops any dazzling and doesn’t obscure your vision, so you can carry out normal everyday tasks while you’re receiving your dose of light therapy.
The company recommends using the device once a day, for around 30 minutes, and by doing so you should start to see a shift in your circadian rhythm in around 4-5 days. Apart from the phase-shifting aspect, Luminette users should expect to feel a boost in energy, especially in the dark winter months, when seasonal mood disorders are most prevalent.
Luminette does have an app, but the software functionality is very limited, so it’s best to think of this wearable as a standalone device. So, if you’re looking a light therapy wearable with a proven history of efficacy and research, and you’re not fussed about smartphone integration, then Luminette 3 is a great choice.
Drive – light therapy for your car
Light therapy for your morning commute
Ok, so this isn’t exactly a wearable, but you could say it’s a wearable for your car. … Drive, a brand new product for 2021 from Lucimed, the makers of Luminette is the only light therapy device that you can use while driving your car.
Drive clips to your sun-visor and is held by both a magnetic clip and an elastic securing strap. If doesn’t interfere with your driving thanks to light being placed above your eyeline making Drive safer to use than a regular light therapy wearable which may obscure your view of the road.
As with Luminette, Drive features 3 intensity levels, a USB charging port so you can permanently install the device in your car, and a rotation hinge to you can easily modify the light intensity for optimal visual comfort. Simple one click operation gives you a 20 minute session with a single button press.
Drive is perfect for those who have to get up early to drive to work when it’s dark or the sun hasn’t risen fully. Or when you’ve had to get up too early and it’s a cloudy and gloomy day. With Drive you can effortlessly and safely get your light therapy in your car, on your morning commute, or in the afternoon to give you an extra energy boost.
Drive retails for $149 and ships worldwide.
First ever ‘discreet’ light therapy wearable
Sula Glasses Quick Specs
- Website: – https://www.sulasleep.com/
- Light source/colour: – Blue-turquoise (peak 470-480 nm)
- Session duration: – 30 mins
- Brightness/luminosity: 100 – 500 lux
- Typical battery life: 7 days
- Weight: n/a
- Wireless charging: No
- Bluetooth: Yes
- App features: Jetlag, Shift work, Energy Boost
- Price: $139
Last, but certainly not least, we have Sula Glasses from Irish consumer technology business, Sula, founded in 2018 by engineers Damien Kilgannon and Mark Caughlan.
Although the term ‘light therapy glasses‘ is often used for a lot of the devices we’ve covered here, Sula is the first company to really stake a claim to this description. Because as well as being a piece of cutting edge sleep technology, Sula Glasses are also a regular pair spectacles, in which you can even fit your own prescription lenses – hence the world’s first ‘discreet light therapy wearable”.
Hidden inside the frames and arms of the specs are lightweight electronics that deliver blue-turquoise light at a luminosity of 100 – 500. The LEDs themselves are located at the bottom of the frames, pointing light upwards towards your eyes.
Fitted standard are special ‘artificial light filtering lenses’ which when worn in the evening time will help prevent circadian disruption from laptop screens, and other gadgets.
Sula recommends you wear the glasses for 30 minutes to get the best benefits. There’s also a companion smartphone app which allows you to input times for shift work, a long-haul travel schedule flight or your fitness training schedule and the app will create a tailored light therapy plan to suit your specific needs.
Pegasi II light therapy glasses
We also must mention the Pegasi II light therapy glasses. We really liked them and you can find out a lot more in our Pegasi II review.
It’s not quite ready to go yet, but hopefully later this year, Canadian startup Lumos Health will have some news on their product release.
A super exciting collaboration between ex Apple/Xiaomi designer Lucas Wen, and world-renowned sleep researcher Jamie Zeitzer, Lumos (previously Lumos Flux) are maybe the sleekest designed light therapy wearable we’ve seen yet.
Like Sula Glasses, it’s an actual pair of glasses, but features a ton of highly innovative product design elements. As soon as we have more news on Lumox Lux, we’ll update you!
More info: Lumos Glasses
What is light therapy?
First some basic definitions. Light therapy, sometimes called phototherapy, or bright light therapy, is the use of light to treat a very broad range of health and medical conditions. Of these, light therapy is considered a ‘gold standard’ treatment for seasonal affective disorder, (SAD) aka the ‘winter blues’ and is also used to treat a range of other mood disorders.
In this article however we’ll be focussing on new and exciting applications for bright light therapy – ie sleep and circadian rhythm problems, which include insomnia, morning sleepiness, shift-work, jetlag, delayed sleep phase syndrome and more.
Light boxes vs wearables and glasses
Clinical bright light therapy for SAD has been around since the 1980s. But the standard treatment method – using a special type of lamp called a light box hasn’t been updated in all this time.
A light box is essentially a bright white light source, usually outputting at least 10,000 units of lux at a specified distance. A typical protocol is to sit in front of the light box as soon as you wake up, for around 30 minutes.
Whilst there are indeed measurable benefits to traditional light box treatment, the drawbacks are pretty obvious. For one, you have to sit still, at the time when most of us are rushing around, trying to get ready for work or a busy day ahead. Secondly, because you have sit at a distance, the light source is by nature, very bright and intrusive.
Light therapy glasses and wearables by contrast are small and portable. So you can still get your light boost in the morning, but instead of being anchored to your chair, you can get dressed, brush your teeth, have breakfast, work out, or even have an early morning conference call.
And because these wearables are worn close to the eye, the brightness of the light source can be relatively dim (in comparison to a standard light box), which means they’re more discreet, won’t blind anyone when you’re having a conversation, but you’ll still the benefits of sitting in front of a large, very bright light box.
Light Boxes vs Light Therapy Glasses Quick Comparison
|Typical light Box||Typical light therapy wearable|
|Size||Large/ bulky||Small/ ultralight|
|Positioning||Correct angle at distance required||Wear and forget|
|Luminosity||10,000 lux at 30cm||35 – 40 lux at eye level (equival to 10,000 lux at 30cm)|
|Light colour spectrum||Full spectrum white light||Blue enriched white light, mono-chromatic blue/green light|
|Power requirements||Generally mains power only||Long battery life (up to a week)|
|Smarts||None.... maybe a timer||Advanced app functionality|
Humans and the sun – an ancient relationship
I pretty much flunked biology in school, but I vaguely remember being taught about how plants synthesise sunlight into energy. It’s kind of taken for granted that all life on earth has an immutable bond with the 4.6 billion year old ball of plasma we call the sun.
So it’s odd, that we’re not taught at a young age about the critical human relationship between sunlight, metabolism, energy and overall cellular health.
Granted, much of this knowledge has been unearthed in relatively recent scientific discoveries, but in the 21st century we seem to have largely ignored the vital role that sunlight plays across the spectrum of human well-being.
We don’t have the scope to dive into all the aspects of what’s been called the ‘new science of sunlight‘ so for the purposes of this article, we’re going let’s zoom in on just one aspect, sunlight’s impact on our body clock, which of course has huge implications for how we sleep.
Whilst we’re on the subject, check out our Sleep Junkies podcast episode with science author Linda Geddes
We are clocks
Circadian rhythms (sometimes called the ‘body clock’) are our internal timekeepers – responsible for regulating not only sleep and wake, but countless other physiological processes including digestion, cellular repair, immune function.
As well as having a ‘master clock’ located in the brain (a tiny clump of neurons called the supra-chiasmatic nucleus or SCN) the human body is made up of trillions of biological clocks, located in almost every cell in the body. And what’s becoming ever more apparent to doctors and scientists is that proper timing and synchronization of these clocks is critical to our health.
So how on earth does sunlight play a role in helping to synchronise our internal clocks?
One analogy I like, is that of an antique watch-maker. Everyday, he checks the church clock in the town square, and then, to ensure all of his timepieces are correct when customers enter the shop, he has to manually wind each minute hand. If he doesn’t do this regularly, some of his timepieces will slowly drift out of sync with the local ‘reference’ time.
Similarly, human body clocks need some assistance to stay aligned with the 24-hour day/night solar cycle. The average human circadian rhythm runs slightly longer than 24 hours so without some kind of external synchronisation cue, our internal clocks may start to become disorganised, and experience circadian disruption, which can have wide-ranging health consequences, including of course our sleep/wake rhythms.
Fortunately however, nature has provided an exquisitely simple, but at the same time, incredibly complex way to wind our metaphorical minute-hands every day…. the falling and the rising of the sun.
How sunlight wakes us up
Throughout the day, our body temperature, hormone levels are constantly rising and falling, signalling to us the optimal times to eat, digest, be active, and to rest. But the most significant of these changes happen during the transitions between wakefulness and sleep (and vice versa).
As we open our eyes in the morning, light (optimally, sunlight) starts a chain reaction of biochemical processes. When light hits our retina, it passes through a set of specialised light receptors. These receptors send a signal via the optic nerve to the SCN, which instructs the pineal gland to stop producing melatonin, the sleep-promoting ‘darkness hormone‘ which is manufactured throughout the night.
At the same time, production of cortisol, a stimulating, alerting hormone, starts to rise, reaching a peak at around 9am in the morning. Cortisol, is often associated with being our main ‘stress hormone’, but it also plays a vital role in sleep/wake regulation.
How modern life messes with your circadian rhythms
Up until the industrial age, this 4 billion-year old sunrise alarm setup worked flawlessly, because for 99% of human history, we’ve lived in partnership with nature, waking and resting in synchrony with the dawn and the sunset.
But starting with the industrial revolution, and then the invention of the Edison lightbulb, humans, for the first time, were able to free set their own wake/sleep/work schedules.
Houses and workplaces could be lit up at will. No longer was night-time synonymous with down-time. Work, social activities could continue long after the sun had set.
Undoubtably the modern era allowed huge leaps forward in human progress, but inevitably there were some downsides too – one of them being the disruption to our sleep schedules.
For example, nowadays we take the 9-5 regime for granted. But the truth is, a huge proportion of the population is waking (and going to bed) at sub-optimal times – when it’s still dark outside instance.
Couple this with catch up sleep at the weekend, and you end up with social jetlag – a permanent state of circadian disruption whereby our biological clocks, instead of being anchored to the sun, are constantly flipping back and forth according to the ‘social clocks’ of work, family and societal schedules.
Of course, nobody wants to go back to a pre-industrial age, but the problem remains – modern life is messing with our clocks, and subsequnetly our general well-being. So how we combat some of the negative consequences of fitting the square peg of our circadian rhythms into the round hole of societal commitments?
You guessed it…. this is where light therapy can help.
How light therapy can improve your sleep
Even if your sleep patterns happen to align perfectly with the solar clock, it’s true that most of us, especially outside of summer months spend most of our time indoors, often in dimly lit offices and living rooms.
Humans however, are evolutionarily hardwired to respond to sunlight, which can be of magnitudes 100x or even 1000x brighter than indoors light.
Light therapy is a useful intervention in these cases because it targets and attempts to reset the biologic clock in our brain – just like the watchmaker winding the minute-hand every morning. A pair of light therapy glasses can provide a reliable, accurate dose of safe, bright light that approximates what you would experience being outside on a sunny day.
Hence, with a short dose of light therapy in the morning, you can help to realign your body clock, and shift the phase of your sleep-wake cycle, giving your more energy during the daylight hours, and more likelihood to feel sleepy at a bedtime that’s appropriate for you.
Sleep/circadian problems you can treat with light therapy
Light therapy’s impact on the body clock lends itself to a range of conditions broadly concerned with circadian health. Here’s a quick rundown:
Difficulty falling asleep at night can occur for numerous reasons. If you’ve been diagnosed with chronic insomnia you should seek qualified medical advice and appropriate treatment like CBTi. However, if you’re struggling with sleep because your body clock is out of sync with your natural bedtime, or if you’re an owl, forced to get up at lark schedules, light therapy can help to realign your circadian rhythms so that you’ll feel naturally sleepier at night.
Difficulty waking up
Waking up, especially when it’s still dark outside, can be difficult to cope with if you’re not a natural early riser. A dose of light therapy shortly after you wake up acts like an alerting signal to the circadian system, lessening grogginess and lethargy, and giving you a natural energy boost in the morning. Repeated use can also help to realign your body clock to a more suitable hour for waking up. See Also: The best sunrise alarm clocks and wakeup lights in 2023
Travelling across timezones causes your sleep/wake schedules to be completely out of whack with your body clock. Whether it’s for work, or even a leisure break, you want to feel energised and at your best when you reach your destination. A carefully planned light therapy program can minimize the negative effects of jetlag by gradually shifting your circadian rhythms to match the local time at your final travel destination.
Shift workers, and especially nightshift workers, face enormous challenges in adapting their body clock to fit work schedules that often change, rotate and turn day into night. Research has shown that bright light therapy, and other interventions such as melatonin supplementation can be an effective strategy to help night shift workers to adapt to their schedules.
If you work in a dimly lit environment, or you’re generally tired during the day, light therapy glasses are an ideal, safe way to give you a direct energy boost when having an afternoon slump because they simulate the natural invigorating effects of being in bright sunlight. Light therapy is an excellent alternative to OD’ing on coffee, Red Bulls, and even naps (although we’re great nap evangelists here!)
Using light as a medicine
We’ve known about the medicinal benefits of light for thousands of years (here’s a brief potted history) and today, in the 21st century, there are several medical practises and interventions that incorporate light as a healing element.
One of the most common is for treating seasonal affective disorder (SAD), aka the ‘winter blues’ which traditionally involves sitting in close proximity to a bright light source known as a light box. Similar bright light therapy protocols are also used to treat depression, bipolar disorder and other mental health conditions.
Photodynamic therapy (PDT) is another medical treatment that utilizes a light source alongside a photosensitizing drug and to eradicate abnormals and is used for a range of conditions including certain cancers, urinary tract infections and gum disease.
There’s also ultraviolet light therapy which uses light to treat a broad range of skin and dermatological diseases including acne and psoriasis.
And finally, much touted by biohackers as a means to enhance testosterone, aid recovery, improve cognition, we have red-light therapy. The science and clinical evidence behind red-light therapy is not as rigorous as in the other fields mentioned above, but it’s worth checking out if you’re curious.
Cautions, risks and side effects
The risk profile associated with light therapy, whilst not zero is pretty low. There are no long-term reported side effects, and any adverse conditions that arise soon dissipate if treatment is stopped.
Because light therapy wearables are so new, most of what we know about side effects comes from reports of people using light boxes. In these cases a small number of users have reported headaches, eyestrain, irritability and other mild mood problems.
For certain individuals, it’s advisable not to use light therapy at all, because of possible complications from existing health problems. So, if you fall into one of the following categories, you should probably stay clear of using light therapy and take advice from your doctor.
Don’t use light therapy if:
- you have a skin condition which makes you sensitive to light, such as some forms of lupus
- you’re taking medications that magnify the harmful effects of sunlight
- you have an eye condition and you’re eyes are vulnerable to light damage
- you suffer from bipolar disorder
- you suffer from frequent headaches
- you are under 12 years old ( our eyes are still developing up until this point)
When should I wear light therapy glasses?
Guidelines vary from manufacturer to manufacturer, because each wearable has slightly different optical properties. But as a very general rule, if you want to optimize your sleep by using light therapy, the idea is to wear your glasses first thing in the morning -usually for around 20-30 minutes – to simulate the rising sun.
But lots of people use light therapy for its energy properties, in which case you might want to use your device in the morning coffee break, midday, or after-lunch time to counteract the post-prandial circadian slump.
Can I use a light therapy wearable if I wear glasses?
Short answer, yes. In fact, there are even a couple of devices (Sula Health, and the still in development Lumox glasses) that you can equip with prescription lenses so you don’t even have to carry your normal specs with you.
Isn’t blue light harmful for me?
Short answer again… no.
Longer answer.. there’s been a lot of media coverage in recent years about the harmful effects of blue-enriched light from phones, tablets and laptops. And indeed, if you’re using technology before bedtime, this will act as a ‘brake’ on your natural secretion of melatonin, preventing you from feeling sleepy, when you really should be nodding off.
But this is only a problem at night. In the morning and daytime, blue light as part of the natural spectrum of colours in sunlight is crucial for proper circadian health and indeed light therapy wearables are designed to mimic the properties of the sun in this way. Just don’t wear them at night!
What’s the difference between white light, blue light and green light?
The field of light therapy wearables is very new, so it’s interesting to see how different manufacturers have taken different approaches to designing what they consider to be an optimal light source. For instance, Luminette uses white light, but enriched with blue wavelengths that peaking at around 468nm. Propeaq by contrast, uses a pure 468 nm monochromatic blue light source. Retimer and Pegasi light therapy wearables have chosen LED light sources that are closer to green spectrum light that blue.
Right now there’s no scientific consensus on which type of light source is best for optimising sleep; blue light, green light, or full spectrum white light. Anecdotal evidence seems to indicate that all of the various options (blue, white, green) have some efficacious effect, but until widespread clinical trials are carried out comparing all of these difference, then we won’t have a definitive answer for a long time.
So the best you can do is to read all of the scientific literature that the various wearables companies have published and make the best informed decision you can.
Let’s talk about lux…
In talk of light therapy, you’ll regularly hear ‘10,000 lux’ being stated as a benchmark measurement of how bright you light source should be. But what does 10,000 lux actually mean?
Without getting into the weeds too much, lux can be considered a unit of light measurement where ‘area’ is also taken into account. Technically speaking, one “lux” is one lumen per square meter, one lumen being the light intensity of a single candle.
So, as a completely ludicrous, not to mention health and safety-contravening concept, if you can imagine sitting one metre away from 10,000 lit candles, then you would be experiencing 10,000 lux.
As we discussed earlier, lux levels throughout the day can vary wildly, depending on our environment. Typical office lighting is anywhere from 300-500 lux, but being outdoors, depending on cloud cover or blazing sunshine, you may experience anything from 10,000 – 100, 000 lux.
But here’s where things get complicated. Bear with me on this…..
Traditionally, anyone involved in taking optical measurements, has worked with a model called photopic vision, which tries to approximate what the human eye/brain perceives in terms of colour and brightness. It is based on three types of cones which generally appear blue, green and red, respectively to the human eye.
But measurements such as lux, are all based on the theoretical response of the standard human eye and brain, relying on elements of psychology as much as they do physiology and physics – because each individual is different, and light/colour perception differs across age ranges, genders, and even cultures.
However, in 2007, a landmark scientific paper was published, challenging the assumption that rods and cones were responsible for mediating all “visual” responses to light.
In short, the paper described the workings of a separate visual system in the eye, consisting of a network of photosensitive ‘ganglion cells’ (or intrinsically photosensitive retinal ganglion cells – iPRG) whose key function was not vision per se, but to interpret light as a signalling cue for the circadian system.
Ganglion cells express a photopigment called melanopsin and this mechanism for entraining the body clock (environmental light > iPRG > melanopsin > brain > I feel sleepy/awake) works even in individuals who are functionally blind.
If you’re still with me, you may be asking, how on earth is this relevant to light therapy wearables? Well, when I quizzed Lucas Wen, CEO of Lumos Health about the lux stats for his new upcoming wearable, he gave me this response:
“this is a complex field as lux is a function integrated with respect to the human photopic curve, which may not be most accurate response curve that is exhibited by ganglion cells for circadian rhythm. In the following study, measuring light in the melanopsin age, authorities in the field propose a new lux measurement standard, with a response curve fitted to that of the melanopsin cells, to better capture the effect of wavelength on neurobiological and circadian rhythm effect. Our co-founder, Dr. Jamie Zeitzer, also recommends using this new lux to characterize effect.”
In short, old ways of measuring lux do not take into account that the response curve of light as a pathway for circadian entrainment (ie shifting out sleep/wake timing an energy boost, mitigating jet-lag), is totally different to the response curve of our ‘visual’ system. Ganglion cells/ melanopsin is most sensitive to short-wavelength (∼480 nm) blue light, whilst the peak of the photopic curve/visual system is around 555 nm,
Disregarding all the physics/biology, the takeaways are simple. If you’re using light therapy to optimize your circadian function/mood/energy, then ‘lux’ on its own, becomes somewhat of a heuristic if you don’t also take into account the specific wavelengths of the light source.
As a good example, Propeaq glasses emit only blue light, so their overall lux output is only around 30-40 lux, but it can achieve a comparable melanopsin response as white light which has ~10x the lux value.
All of this is very new stuff, and in truth, the technical standards, the research, the clinical trials are nowhere near validating the scientific theory yet. But, to use an analogy, with a car – you don’t measure it’s speed just by the horsepower. And it’s the same with light therapy wearables. Absolute lux values are only part of the story – there’s a lot more under the bonnet to consider…!
Our guide to the best light therapy wearables in 2023
So now we know all about the principles of what light therapy can do, but let’s get down to the nitty grity – what are some of the best wearables and glasses on the market right now?
The good news is that this is a really dynamic, innovative space and there aren’t really any bad products in this sector (….yet). But what we do have are 6 wearables that all do things a little differently, in terms of design, form and function.
Some place more emphasis on aesthetics, with others eschew good looks and focus more on health and wellness. Some light therapy wearables are designed with travel and portability in mind, others are more suited to use at home.
Other considerations include; whether you want a device that has integrated app functionality, or if you prefer standalone products; snazzy looks; battery life; wireless charging and whether scientific validation is a deciding factor in your purchase.
All that said, here’s a comprehensive look at our top picks in 2023 for the best light therapy glasses and wearables you can buy right now.
If you made it this far, then obviously you’re as excited as we are about the exciting potential of this new wave of health-promoting technology. Light therapy has numerous benefits, and the downsides are few. And with so much innovation going on in this niche of the consumer sleep technology market, it’s a great time to explore the options out there and maybe jump in and try to see if light therapy can offer you any benefits.
For disclosure, we try to be as objective as possible. Some products we have relationships with where we get a small commission if you purchase via a link on our website – it’s how we make a living. But for many products we have no financial relationships with – we just like to represent the best of the best, and leave you to make your choices. If you want to know about our own personal experiences, you can read our in-depth user reviews.
Our bottom line advice is that if you think a particular device might be the ticket for you, go ahead, make a purchase…… with one caveat – always make sure you can get a money-back guarantee in case it doesn’t work out for you.
As always, if you have any questions about anything, you can always email us directly and we try to answer every query we get. Good luck, and may the sleep be with you!