Sleep and Blue Light

There’s nothing worse than finally going to bed after working all evening and finding that you can’t fall asleep. One easy change that might help is to limit the amount of blue light you see in the hours leading up to bedtime. Below are some ideas for you.


In 2012, the American Medical Association’s Council on Science and Public Health made this recommendation: “Recognizes that exposure to excessive light at night, including extended use of various electronic media, can disrupt sleep or exacerbate sleep disorders, especially in children and adolescents. This effect can be minimized by using dim red lighting in the nighttime bedroom environment.” [via F.lux’s website]


More and more research has come out about late-night screen time and difficulty getting to sleep. Phones, tablets, and computers (TVs too!) put out light that tends to be blue-shifted. This is great when you’re working during the day, but in the evenings that blue-shifted light can signal to your body that it’s not getting close to bed-time.

Ideally, researchers would like us to turn off all of our devices a few hours before bed, so that the screen time doesn’t interrupt or diminish sleep. Realistically, busy parents and students can’t (or won’t) avoid phones and computers for hours before going to bed; they’re both useful and tempting. So, there are some hacks.

For your computer: Flux is free software for Macs and Windows computers that will red-shift (less bad for sleeping) your screen at night, and then bring it back to normal in the morning. If you are using your screen to design something where color matters and Flux is causing havoc, you can disable it for an hour, until sunrise, or for the current app. The yellow-y look to your screen at night takes some getting used to, but seems worth adapting to for better sleep.

For your phone: Flux also runs on Android phones, and for those with iPhones, the recent iOS release includes “Night Shift”, which does basically the same thing as Flux.

To enable Night Shift:

  1. Go into Settings.
  2. Scroll down to Display & Brightness.
  3. Tap Night Shift.
  4. Choose your settings (I go with Scheduled, from Sunset to Sunrise).

In a related vein, if your iPhone is simply TOO BRIGHT when you compulsively check it in the middle of the night, no matter now low you turn the brightness, there’s a bit of a hack for that too.

To (further) dim your iPhone’s brightness:

Settings -> General -> Accessibility -> Zoom

  1. In Zoom, select the Zoom Filter “Low Light”
  2. Back in Accessibility at the bottom make sure that the Accessibility Shortcut is Zoom
  3. Now if you click the home button 3 times in a row, it will turn on or off Low Light.


Have you tried changing the settings on your digital devices (or instating a screen-time curfew) to help you sleep? What worked for you? I’d love to know in the comments below.

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