Sleep is incredibly important to our physical and mental health. Research suggests that a chronic lack of sleep can have all kinds of negative repercussions, from heart disease and diabetes to impaired attention, alertness, concentration, and more.

In fact, at least one study showed that reducing sleep from seven hours a night to five or fewer hours almost doubled the risk of death from all causes. Our modern lifestyles include many factors that lead some people to get less sleep than they should, and our many gadgets could be some of the worst offenders.

And it’s not just the constant bombardment with sights and sounds that are at fault — some researchers submit that it’s the light emitted by our devices that is causing many of us to sleep fewer hours, and for the sleep we do get to be less restful. Thankfully, there is a solution; you just need to learn how to use a blue light filter on a PC or Mac.

The reason blue light hurts is purely biological. Sleep is a part of the circadian rhythm, the cycle of biological processes that’s determined in part by the amount of light and dark to which our bodies are exposed. In the most natural setting, which is one where we’re only exposed to sunlight, our retinas sense when the sun is going down and the environment is getting darker. That induces our hypothalamus to tell the body to produce melatonin and other sleep hormones and to reduce our body temperature.

When we use artificial lighting to extend our day, however, our bodies get confused and the various sleep signals are disrupted. Even worse is the blue light that’s emitted by fluorescent and LED lights — like those on our various device displays — and that actually causes us to be more alert and to produce even less melatonin.

So, what’s a person to do in our modern world where using technologies that produce copious amounts of blue light seems unavoidable? The answer is to find ways to block the blue light that our devices emit, if we’re determined to use them well into the evening hours.

Windows 10 and MacOS have recently gained their own special blue light limiting features, and we’re going to show you how to make use of their potentially health-improving benefits.

Windows 10

Microsoft added a blue light limiting feature to Windows 10 in the Creators Update that was released in April 2017. Called “Night light,” this feature shifts the Windows 10 display to show warmer colors that reduce the amount of blue light that’s emitted.

Turning the Night light feature on is a simple enough process. Just go to the Action Center and click on All Settings, then click on the System button, and then select Display. Night light can be toggled on and off.

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To configure the Night light feature, click on Night light settings. Configuration options include the ability to turn the Night light on immediately, adjust the color temperature while the feature is enabled, and schedule when the Night light will turn on and off.

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To set the schedule, toggle the Schedule night light option to on. Then, you can either choose to let Night light turn itself on at sunset and off at sunrise — automatically determined by your location — or you can set the time manually by clicking Set hours and choosing when the feature should turn on and off.

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When you first turn the feature on, you’ll notice the color shift immediately. After a while, your eyes will adjust to the change and it should be less intrusive. By reducing the amount of blue light, however, the Night light feature will now be limiting the impact of using your Windows 10 PC late at night — you could find it easier to get to sleep, and your sleep might be deeper and more restful.


Apple first implemented its own blue light limiting feature, dubbed Night Shift, in iOS 9.3. That helped out the company’s iPhone and iPad users, but it did nothing for MacOS users who were more apt to prop up their MacBooks in bed before turning in. Fortunately, it didn’t take Apple long to bring Night Shift to MacOS, with the feature debuting in MacOS Sierra in 10.12.4 in March 2017.

As with Windows 10, the feature is easy enough to turn on and configure to your tastes. To get started, open System Preferences and select Displays, then click on the Night Shift tab.

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On this settings page, you can configure when the Night Shift feature will automatically run, turn it on until the next day’s sunrise, and set the color temperature to your preferences. In terms of scheduling, you can let MacOS turn it on and off at sunset and sunrise based on your location, or you can set a custom schedule.

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Just like with Windows 10’s Night light feature, Night Shift will make your display’s colors warmer and reduce the amount of blue light that’s emitted. Give it a try to see if it improves your sleep habits and lets you be healthier, more productive, and generally a happier Mac user.