Blue Light Therapy for Sleep (The Ultimate Guide)

You’ve probably heard before that we spend one-third of our lives asleep.

To the aspiring individual, that figure seems to be a shameful state of affairs – a disasterpiece of the modern work ethic.

Sleep deprivation is now seen as the pinnacle of productivity – and you’re expected to play along. Somehow, the drooling mess that remains when a generous portion of sleep has been removed from an otherwise sane individual has become an icon of efficiency.

In fact, this “social jet lag” is so common that it’s practically normal. With so little free time and the inability to sleep early enough, jolting out of bed at an ungodly hour has become the only way to stay afloat in the rat-race of the 9-5. Some people even voluntarily play this game of competitive sleep deprivation, ironically, in the hopes that they can work hard enough to escape it; while others wear it as a badge of honor to secure bragging rights after a night of debauchery.

In the end though, the only way to make this chaos sustainable on a weekly basis is to partake in the sacred ritual of catching up on sleep at the weekend. So, yes, we do spend a whole third of our lives asleep, but we should be more concerned with the other two-thirds that we spend sleepy.

Of course, the common solution to daytime sleepiness is to either guzzle coffee and hope for the best or to simply just cope with it. However, for “night owls” – people who live with Delayed Sleep Phase Syndrome or Non-24-Hour Sleep-Wake Disorder – this is the only way of living because it isn’t caused by lifestyle choices or workaholic tendencies.

Actually, that’s not strictly true… there is in fact a far better way to beat this chronic misery: a way which doesn’t involve caffeine addiction, yet can raise energy levels, fix your sleep schedule and even fight depression.

And, I’ve personally used this method to move my bedtime back by 7 hours in one day.

Want to hear it?

Well, to understand how it works, I’ll have to explain something about your eyes.

Journey to the Center of the Eye

The story begins in 1923 with an ambitious researcher by the name of Clyde E. Keeler.

Now, up until that point, it was thought that there were two kinds of light receptors in your eyes that enable you to see: rods and cones. Rods are so sensitive that they can even be triggered by a single photon, which makes them pretty good at their job: providing you with both peripheral and low-light vision, allowing you to spot that shoe out of the corner of your eye which you were just about to trip over while getting ready for work in the light-forsaken darkness of the early morning.

They’re like the black and white telly of photoreceptor cells: they get the job done with a reasonable picture quality but lack any capacity for color.

That’s where cones come in.

Cones don’t simply perceive color – you’re actually reading this with your cones right now using a densely packed, rodless area at the center of your retina called the fovea centralis, which is responsible for your sharp central vision. When this area lines up with a point in the world, such as a word on the screen, the point becomes clear and distinct. Leonardo Da Vinci – a clever bloke as you may well know – was the first person to discover this.

Anyway, the gist is that rods are low resolution but let you see outside the center of your vision even when it’s dark, while cones are high resolution and let you see color. Makes sense. However, there’s a piece of the puzzle missing.”I went into my career with my eyes open,” said Keeler. And that he did.His lab mice, however, were not quite so perceptive.

While looking at the eyes of a male albino mouse for the purpose of studying the retina, Keeler realised that he had accidentally bred it totally blind. Just to be sure, he checked the eyes of two of its brothers and found that they too lacked rods and cones. “Failure to find the visual cells in these two cases was obviously not to be ascribed to their loss through faulty technique,” thought Keeler, knowing fully well that something was up. He bred more of these blind mice in the name of science, and began to notice something that just didn’t make sense.

Despite completely lacking all rods and cones in their eyes, these mice still responded to light. In effect, he had discovered a third type of receptor in the eye.Fast forward to 2002, when these receptors were properly identified by Samer Hatter, David Berson and their colleages, who, instead of giving them a name like “spheres” or “blobs” to go along with the shape-based naming convention of “rods” and “cones”, gave them an accurate but completely unmemorable name: intrinsically photosensitive Retinal Ganglion Cells, or ipRGCs for short.

These cells play a vital role in non-image forming vision and are by far at their most active when exposed to a specific wavelength of blue light between 475 – 480 nm: a wavelength which is present in sunlight.

This is the reason why these cells are key to solving your sleep problems. They interpret this wavelength of blue light to mean “WAKE UP!” – shifting your circadian rhythm and suppressing the release of melatonin.

How to Biohack Your Sleep: the End of Social Jet Lag

In order to fix your sleep schedule and eliminate daytime sleepiness, you need to understand what the circadian rhythm actually is and how you can use blue light to shift it.

It’s a little counterintuitive because we usually associate tiredness with a simple lack of sleep – but that’s only part of the picture. That kind of tiredness is called the homeostatic sleep drive, which is just a fancy name for the feeling of “I’ve been awake far too long and I need some sleep.”

However, there’s actually a second kind of tiredness which varies during the day. You’ve probably noticed before that if you try to go to bed too early you’ll basically end up tossing and turning for hours until your normal bedtime comes around.

That’s because you’re trying to sleep at the wrong point in your circadian rhythm.

This rhythm: your “body clock” or “biological clock” – as you might have guessed – repeats every 24 hours, dictating when you should be asleep and when you should be awake. It dips low during the night and peaks during the day, except for an extra half-dip that happens around midday.

You know the afternoon slump? Yeah, that’s it.

The way that it does this is no work of magic. Rather, it’s the work of a somewhat banana-shaped hormone called melatonin which truly can drive you bananas if it’s present in your body during the daytime. It’s what you feel when you say that you’re sleepy, released in anticipation of those dips in your circadian rhythm so that you can get some shut-eye.

Of course, that can be an absolute pain if it happens at the wrong time, such as when your sleep schedule is messed up, upside down, or just plain nonexistent. A good way to think of melatonin is that it’s the exact the opposite of caffeine.

In fact, the whole reason why we guzzle coffee after crawling out of bed in the morning is to counteract the effect of melatonin; it’s not like we do it for the jitteriness, anxiety or withdrawal symptoms. Long story short, melatonin is good at night and bad in the daytime.

However, there’s a better solution to your melatonin problems than a cup of coffee. All you have to do is shift your circadian rhythm so that it’s aligned with daylight. And to do this, you can use the fact that your circadian rhythm already aligns itself with daylight – through the intrinsically photosensitive Retinal Ganglion Cells.

When these cells detect that 475 – 480 nm wavelength of blue light, they not only clear your body of melatonin by suppressing its release from the pineal gland, but they also shift your circadian rhythm depending on the time, intensity, and length of exposure. To make this easy, there’s a handy little graph called the human phase response curve, which basically shows you when you should bathe yourself in a generous amount of blue light if you want to shift your circadian rhythm one way or the other.

Blue light exposure in the delay zone shifts your circadian rhythm later, while exposure in the advance zone shifts it earlier. The flip point is 5 hours after your current, and probably highly messed up, bedtime.

The zones extend up to two hours either side of your body clock’s expected wake-up time and sleep time, after which blue light exposure has no more effect.

It’s still advantageous to bask in blue light outside those hours though, since it fully retains its melatonin-clearing, uplifting effects which are especially useful for the treatment of seasonal affective disorder, also known as the “winter blues.”

How to Use Light Therapy to Beat Daytime Sleepiness or Treat Seasonal Affective Disorder (SAD)

Light therapy is pretty simple. All you have to do is put your light therapy lamp at a distance of around 0.5m away from you and have it within your field of view for about 20 to 30 minutes. You can go for a longer session if you like or even just leave it on all day like I do, but keep in mind that using it up to two hours before bedtime or up to two hours after spontaneous awakening will shift your circadian rhythm like we talked about earlier.

You can do anything you like during your light therapy sessions: work, read, exercise, or even play video games if you want to. Anything. If you want some bonus feel-good points then I’d suggest combining your light therapy with a 20 to 30 minute meditation session – it’s the perfect opportunity to do so. You can put your light in front of you, either side of you, above you or below you; it doesn’t matter as long as you’re not looking directly at it. I mean, you could look directly at it without risking damage to your eyes since the blue light, unlike sunlight, contains no UV whatsoever. However, it might be a bit too intense or even just plain painful – especially in the case of those blue-light containing 10000 lux white SAD lamps. Trust your instincts.

All in all, I’ve personally used this method to move my bedtime back by 7 hours in one day. Blue light – of that targetted wavelength – is powerful stuff.

How Many Lux should a SAD Lamp Have?

Don’t be sad if your blue lamp doesn’t match the brightness of the 10000 lux white ones. The only reason that the white light works is because it contains some of the 475 – 480 nm blue light within it, which means these lamps need to be far brighter to get the same effect. Save yourself the eye strain and get a blue SAD lamp.

What’s the Best Blue Light Therapy Light?

The Philips GoLITE BLU Energy Light uses just 200 lux of 475 – 480 nm wavelength blue light to achieve the same effect as 10000 lux of white light. That’s pretty good considering how much eye strain it will save you compared to blasting your eye sockets out with a traditional SAD lamp. You’ll never need to replace the bulb with this lamp, and the light itself is diffused nicely across the screen without any bright spots or glare. Yes it’s portable, but it’s mains only which may or may not be a problem for you. You’d practically only ever use one of these lights while stationary anyway, so I wouldn’t worry about it. However, there are a couple of drawbacks to this lamp that you should know about. For one, the power cable is really short, making it pretty impractical if you don’t have any plug sockets close by. I guess you could use any old extension cable but that’s beside the point. The second downside is that the stand is pretty flimsy and it’s conceivable that it could snap with too much use. All in all though, it’s a very effective lamp for the job and will serve you well in your quest for a decent sleep schedule.If you really want a rechargeable version then you’ll be glad to know that there is one. Along with the 60-minute battery life you also get two extra levels of brightness, a timer, and touch button operation, for the higher price.

However, if you want to go all-out and save money at the same time, then LIFX’s smart bulbs are exactly what you’re looking for. With wifi-connectivity for your own smartphone-controlled luxury, you’ll have 16 million colors at your disposal as well as plenty of shades of white light for when you don’t want to light up your home like a Christmas tree – which is practically never if you’re like me. Of course, you’re mostly interested in that special 475 – 480 nm wavelength of blue light, so I’ll tell you how to get that. In the app, you can set whichever color you like by spinning the color wheel until you get to the hue degree you’re looking for. Red is at 0° (or 360°), green is at 120°, and blue is at 240°.

However, the sky blue color that we’re looking for is between blue and cyan. You should use a hue that’s around 195° for maximum effectiveness. It might seem not right, but it is.

The only downside of using an LIFX smart bulb for blue light therapy is that it requires a light socket to power it. On the other hand, that also makes it pretty versatile because you can use it to convert your table lamp, floor lamp or even your ceiling light into a powerful SAD lamp. Make sure you check which cap type you need to fit your socket. Click here for the omnidirectional A19 version, and click here for the wider forward-focusing spotlight BR30 version. Both of these bulbs have E26 Edison screw caps and will fit either E26 or E27 sockets. You can always get a cheap adapter if you happen to have any other type of fitting, but keep in mind it’ll make the bulb a bit taller. Each one of these is equivalent to a 75 W incandescent bulb.

As with all light bulbs, using a lampshade is necessary to diffuse the light. You’ll preferably want to use a white one so that the color comes through clean and pure, but if you wanted to, you could get away without one at all because its 1100 lux of brightness isn’t nearly as harsh on the eyes as a 10000 lux daylight bulb.One of the best things about the LIFX smart bulb is that you can switch it to red to compliment your light therapy with some dark therapy in the evening.

Dark Therapy Too? Are You Sure You’re Not Making This Up?

Electronic screens, which we all know and love, are one of the most common causes of insomnia because they contain large amounts of blue light, leaving us lying awake at night and feeling groggy in the morning. It’s not that the blue light is bad for you, it’s that we have a tendency to expose ourselves to it at the wrong time: specifically that two-hour window before bedtime which we talked about earlier.

Don’t worry though, you don’t need to deprive your eyes of all light in those two hours for dark therapy to work – only the blue light which wakes you up. To do this, you’ll simply want to set your devices to a warmer color temperature by using nightshift on iOS and installing f.lux on your computer.

Of course, the electric lights in your home will also contain blue so you should either switch them off or switch them to red to prevent any circadian shifting effect. Alternatively, you can use blue light blocking glasses to take care of it all for you: They’re like f.lux for real life.

Swanwick do some really nice ones, pictured above, which are anti-reflective and anti-glare, but you could also go for these ones by Uvex if you’re looking for an inexpensive solution and don’t mind looking like that guy from Team America: World Police.