There has been a lot of buzz around the recently announced Nightshift feature in the upcoming iOS 9.3. It’s not out, yet, but I am really excited about the prospect of finally having something like f.lux on my iOS devices. In fact, it’s one of my most requested iOS (and in-app) features.1 The premise of Nightshift is that your device adapts its screen temperature to the suncycle. Originally, screens are built to mimic the sun’s light spectrum and to concur with sunlight during your daytime device usage. This is why screens are traditionally built to emit light of a blueish spectrum.
With Nightshift, your screen will turn towards more yellowish-reddish wavelengths once the sun sets. This way, with less of a blueish tint, Nightshift is supposed to support your regular circadian rhythm of sleep onset.
Blue light is known to be a strong suppressor of one of sleep’s major regulating hormones, melatonin. Melatonin release is upregulated once ambient light exposure decreases. It’s a process called dim light melatonin onset and it’s easily disturbed when blue light hits your retina. The less melatonin that’s circulating your bloodstream, the less prepared your body is to fall asleep.
So, Nightshift is supposed to better align your device usage with your sleep biology. At least, that’s the theory behind it.
I hope that this new feature in iOS will translate to other gadgets and appliances throughout our daily lives. Light is everywhere in our environment. It’s one of the biggest pollutants that modern day humans have to deal with. This situation is in stark contrast with our evolutionary roots. Ancient humans didn’t adapt to brightness after nightfall, other than maybe fire, moon and starlight. In our history, we probably evolved to sleep in total darkness which is something that many personal bed rooms or hotels these days don’t offer.
Even if we cut back on our blue light exposure through our phones, chances are we are still being radiated by TV screens, light bulbs, cars, LED diodes, halogen lamps and countless other light sources after sunset.
As long as companies of all markets are lagging behind in this aspect, I’ll keep on using blue-blocking glasses in my home after dark. In fact, I have recently found some that don’t look totally dorky.2 The lenses of these glasses filter out blue wavelengths with a slightly yellowish tint. It’s basically Nightshift mode for everything.
I’m a shift worker and so sleep is a big topic for me. I drop in and out of sleep deprivation regularly and I consider sleep one of the aspects in my life that I have to work on the most. Lack of sleep is detrimental and can only be made up for so much by other life style factors like movement and diet. In the end, sleep may be king and be even more important than those. So, we all better get our sleep in order.
In the recent months since I started wearing blue blockers, I have noticed an increase in my overall sleep quality. It has translated in particular to a more stable mood, more mental clarity and better physical performance. The improvements have also been reflected in a higher sleep quality percentage score that I obtain via an app called Pillow. It’s a sleep tracking app on the iPhone that measures your sleep quality as a function of your nightly movements via the motion sensors in the device.3 Pillow has made other apps for this purpose on my phone obsolete and it even replaced the sleep tracking I used to do via my Fitbit Charge HR. This is the case due to a sleep quality percentage that Pillow offers which I find highly actionable. Basically, it’s a function of how well you transition through the different sleep stages, how often you wake up during the night and whether you achieve the desired minimum of 7 to 9 hours of sleep per night. This score has become highly addictive to me and upping the number is a health priority of mine for this year.4 Better sleep just translates into better everything and it’s a key variable in productivity. However, sleep is a complex thing and light exposure is just one of the many factors that play into overall sleep quality.
Humans are highly susceptive towards light5 and we have to increase our awareness around this topic. It’s not just about how easy you fall asleep at night, if you dream or not or how well rested you wake up in the morning. Sleep is a major driver for overall health and disrupted sleeping patterns may be involved in all kinds of illnesses, from heart disease to cancer.
Nightshift mode on iOS is a good step in the right direction. However, I still think light after dark in general (and not just the blue wave lengths) is a bigger culprit for disrupted sleep patterns all over the world. This touches on the question how we are to live our evenings. Are Netflix, checking Facebook and iPad gaming in bed how we should be ending our days? What about winding down with your family, with a walk outside, a soothing bath or some light weight training? In other words, we should be using less screens before bed, no matter how their wave length emission is configured and start being more mindful about the last hours of our days. It’s for the better.
- Some apps that I use on a daily basis like Overcast and Dropbox still don’t offer a nightmode and instead scream at you with white backgrounds. I always have to resort to the „triple-click-the-home-button“ accessibilty feature and invert the screen to make up for this omission. ↩︎
- It’s the one that Michelle Tam recommends on her fantastic Nom Nom Paleo blog. ↩︎
- One of the problems with this, though: you have to have your device with you in bed. I always keep my phone in Airplane mode at night, but it’s probably still better not having it anywhere near you in bed. ↩︎
- I am at 73% in total which might be in a lower percentile of Pillow users, but that’s just to demonstrate where I am coming from. ↩︎
- In fact, it’s not just our eyes that are light sensors. Our skin and our blood also seem to be involved in transmitting light signals throughout our bodies. ↩︎