Experts have long been aware that screens sabotage our sleep, but little has been done to defend us from it. As our reliance on screens grows, however, the technology industry's biggest players have no choice but to take up arms against the threat.
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As consumers are increasingly aware, the bright blue-hued light that emanates from our digital screens is perhaps our sleep’s biggest enemy. It tricks our brain into thinking it is daytime, and suppresses the night-time release of the sleep-inducing hormone melatonin. This problem has been with us as long as the light bulb, but with digital devices permeating every aspect of our lives — and mobile screens often following us to bed — it’s a near unavoidable threat.

But in recent months, something has changed: There’s been a real and radical shift in the battle against blue. Rather than ignoring the problem, major tech companies are, for perhaps the first time, acknowledging it and offering products that seek to eliminate its effects.

“It was imperative that we come up with a solution to limit blue light exposure to alleviate any concerns about reading on their tablets at night,” says Charles Trischler, vice president of Amazon Devices, which recently released a feature called Blue Shade that removes blue light from the company’s Kindle Fire line of tablets.

Steve Young, marketing manager for Philips Displays, which now offers a feature called SoftBlue that filters out blue wavelengths from some monitors, echoes the sentiment. "Blue light is something tech companies can no longer afford to ignore.”  

Understanding the Enemy

The mechanism for how screens interfere with our sleep is actually pretty amazing. Hidden in our eyes among the rod and cone photoreceptors that give us the sense of sight is a third type of photoreceptor cell that was, remarkably, only discovered by Dr. Russell Foster in the 1990s. These so-called “photosensitive retinal ganglion cells” are, as their name suggests, sensitive to light. But unlike rods and cones, they don’t actually allow us to see. Instead, these cells serve as a sort of trigger for when the sun is up, telling our bodies to hold off on the melatonin so we can be awake and alert because, hey, it’s the daytime.


Now, this system worked pretty well for a few billion years, when the chances were high that any light hitting an eye came from the sun. But in the modern world, things are very, very different. Light is, quite literally, everywhere. LED billboards and always-with-us phones and flickering TV screens don’t care what time of day it is, and their light carries the same “you should be awake” message as the sun.

"Blue light is something tech companies can no longer afford to ignore.” 

“Because of the three-to-four billion years of evolution of light during the day and darkness at night, our body clocks are not expecting light at night,” says Randy Nelson, Ph.D., the chair of neuroscience at Ohio State University’s Wexner Medical Center

To make matters worse, these photosensitive retinal ganglion cells don’t actually treat all light the same way. While red and orange lights can hit them without causing much of an impact, these cells are uniquely sensitive to the short wavelengths of blue light. And as luck would have it, the screens that surround us seem to be uniquely good at shooting out just this sort of light.

“Most of our electronic screens are mainly blue light,” Nelson says. “Fluorescent — including compact fluorescent lights — lights are blueish. If you walk down the street at night, you’ll note that there is a blue glare coming from the living rooms from the TVs.”

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To fight this threat, science-savvy consumers have long had access to arsenal of tools. There are blue-blocking glasses and screen shields, as well as a popular software plug-in f.lux that gradually filters the low-wave light out of a computer screen as the sun sets, allowing users to ease into a mostly blue-less display. What’s different now is that tech giants such as Amazon, Acer, Philips and even Apple are building anti-blue features directly into their products.

"We've Reached a Tipping Point"

So why now? According to Lorna Herf, co-creator of f.lux, the one-two punch of widespread mobile device use (especially in bed) and a slew of high-profile studies on the effects of backlit screens — particularly a news-grabbing December 2014 study published in the Proceedings of the National Academy of Sciences that measured the effects of screens on sleep — have created an environment where tech giants can no longer afford to pretend like blue light isn’t a problem.

“The press from this article was enormous, and it struck a nerve with a lot of people, so manufacturers scrambled to find an answer,” Herf says. “Now everyone from totally see-through eyeglass coatings to monitor manufacturers is advertising that they’re blocking blue light to protect sleep.”

We’ve likely reached a tipping point where the rest of the industry will soon hop on board the anti-blue bandwagon.

One watershed moment: Apple’s recent release  of“Night Shift”. When activated, it transitions the colors in the company’s mobile screens to align with the sun — i.e brighter in the morning, and dimmer and free of blue light as night falls. 


Needless to say, having this feature on every iPhone and iPad on the market is a big deal, and with so many major names on board, we’ve likely reached a tipping point where the rest of the industry will soon hop on board the anti-blue bandwagon. After all, companies like Apple and Amazon are amongst the few out there capable of turning a new feature into a must-have industry standard. And if these features do end up having real and noticeable health effects on users, there will likely be added urgency behind other companies’ efforts to come out with their own version of Night Shade or Night Shift.

From a public health perspective, building anti-blue features directly into mainstream consumer products has a huge upside.

“Companies often quickly respond once one has implemented a feature that can improve a device user's experience,” says Ross Rubin, a longtime technology analyst who is currently serving as senior director of industry analysis at App Annie. “Years ago, we saw something similar with optional software-defined volume limits that spread quickly among devices.”

From a public health perspective, building anti-blue features directly into mainstream consumer products has a huge upside. While f.lux is effective and very easy to use, it doesn’t work with all of our devices (Apple actually told its creators to take down an iOS version just months before announcing its Night Shift feature.)

As companies increasingly put anti-blue features into their products, it’s going to be more important than ever to separate which ones really work.

For consumers, there are also potential product advantages to building these features directly into devices, instead of relying on third-party software. For one, hardware manufacturers can adjust how their screens physically deliver light, in order to make it a bit easier on the eyes.

According to Amazon’s Tritschler, the new features allow the screens to be dimmed to a minimum brightness that was not previously possible (if you’ve ever looked at a bright LCD screen in bed in the dark, you know this is a big deal). And Philips’ Young claims that the company is “actually tweaking the chemical makeup of the LEDs and adjusting the signal to ensure that we were able to maintain white and vivid colors while protecting eyes from harmful shortwave blue light.”

Of course, as companies increasingly put anti-blue features into their products, it’s going to be more important than ever to separate which ones really work, and which are just marketing gimmicks with, literally, ruby-colored glasses. For example, some existing anti-blue software products give screens a red tint, but actually do little to limit blue light.

“Much more research is needed before we can say that any of this actually makes devices safe to use in the middle of the night,” Herf says. “Every company offering a solution needs to be focused on constantly trying to disprove their own ideas and assumptions and contribute to the science.”

Not all options may work. But at least the battlelines have been drawn.