Protect Your Eyes from Your Screen’s Blue Light

The facts about blue light, why you need to know about it, and how you can manage your exposure.

We live in a world of screens. From our phones and tablets to televisions and computers, the average person spends roughly 9 ½ hours a day looking at a screen of some kind. Every one of them puts out ultraviolet light, or “blue” light, and being exposed to so much blue light is becoming a problem for our eyes, sleep patterns, and overall health.

To make a really complicated issue way too simple, the basic issue with blue light is that it tricks our brains into thinking it’s daytime. So if you use your phone in bed at night, your brain stops preparing itself — and you — for sleep and instead stays as active as it would in the afternoon.

There are lots of claims about the harmful effects of blue light, that it causes everything from headaches to insomnia to diabetes. But just how harmful is it?

What Is Blue Light?

Let’s go back to science class for a minute. Blue light isn’t technically blue. It sits at an invisible portion of the light spectrum, but it’s closer to the “blue” (ultraviolet) side than the “red” (infrared) side. Blue light waves are shorter, more compact, and have higher energy than light lower on the spectrum, so they have a stronger effect on your eyes.

The sun is, by far, the biggest source of blue light. And that light is actually good for you. It makes you alert, improves your mood, and boosts your body’s production of vitamin D. Blue light scatters easily, which is why the sky looks blue on a cloudless day (not because it reflects off of the ocean).

Our digital devices are the second biggest source of blue light, which is problematic. When we experience blue light from the sun, it’s because it’s the daytime. When we get blue light from screens, it could be any time of day, which confuses our brains.

What Does Blue Light Do?

Besides telling our bodies it’s daytime, blue light also decreases melatonin levels, which is a natural chemical that helps you feel tired. So, if you’re having trouble sleeping, you might be seeing too much blue light at night. A recent clinical study had one group of people read a physical book, and another group use an eReader. When they tried to go to sleep, the group that used the eReader took longer to fall asleep, had less time in REM (a crucial part of the sleep cycle), and woke up feeling more tired than the group that read a physical book.

Overexposure to blue light can also cause eye strain, drowsiness, and headaches, and has even been linked to macular degeneration, a leading cause of blindness in adults.

What Can You Do about It?

Given how many screens we’re surrounded by, it might seem impossible to escape the blue-light nightmare. But it’s not. And there are some easy ways to manage your exposure to blue light and its effects.

The easiest thing to do is filter blue light on your devices. Phones now include a standard feature that reduces blue light by boosting softer, warmer tones.

    • On iPhones, tap Settings > Display & Brightness > Night Shift.

From here, you can schedule when your phone will reduce its blue light output. You can also manually enable the feature, as well as adjust how warm or how blue the light should be. Try it out and you’ll immediately notice the difference, with the screen’s blue light becoming a softer yellow. Move the slider toward More Warm and the light becomes almost reddish.

    • On Android devices, tap Settings > Display > Blue light filter (or Night light).

From here, you can turn on the blue-light filter and adjust its intensity, from a warm yellow in the midrange to a reddish hue at the far, non-blue end of the slider. You can also schedule when the blue light filter is active by either setting to a custom time or to be on from sunset to sunrise.

These blue-light filters are designed to be used at nighttime, but you can turn them on at anytime of day and even use them all the time to really scale back your exposure.

Take a Break

Every 20 minutes, stop looking at your screen and look at something 20 feet away. If you think you’ll forget, set a reminder on your phone to make sure you give your eyes a break.

Even if you don’t think blue light is a problem for you, it’s good to get into the habit of taking short, periodic breaks from your screens to give your eyes a rest.

Wear Protective Glasses

If you spend a lot of time on the computer for work or school, you can buy glasses specifically designed to block blue light before it hits your eyes. You can purchase these glasses with or without a prescription. Gauss, Felix Gray, and PupilBox make good protective eyewear, but there are plenty of other options out there, too.

Now that you know a little more about blue light, you can protect your eyes and sleep schedule — without giving up your phone.

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