Today, Apple announced a new feature called Night Shift as part of their next software update. It will automatically adjust the colour of your iPad or iPhone when it gets dark. Why? It’s all about sleep problems.

According to Apple: “Many studies have shown that exposure to bright blue light in the evening can affect your circadian rhythms and make it harder to fall asleep. Night Shift uses your iOS device’s clock and geolocation to determine when it’s sunset in your location. Then it automatically shifts the colors in your display to the warmer end of the spectrum, making it easier on your eyes. In the morning, it returns the display to its regular settings.”

Why is blue light at night a problem?

Before the invention of electricity and light bulbs, people relied on the sun for light and used only natural sources like candles, campfires and lanterns after dark. These are all orange-based lights. Today, additional artificial light from computers, TVs, tablets and mobile phones, has extended our exposure to artificial light even more. All of these new technologies are especially high in blue light.

Research shows that blue light after sunset can disrupt circadian rhythms (our 24-hour body clock) and suppress melatonin production but recent studies are showing that this has even more serious consequences. Researchers have known for years that shift workers and those who are regularly up late at night, are at a higher risk for various cancers but more recent research shows that even recreational exposure to blue light for a few hours at night can have a negative effect.

This is a report from Harvard Medical School – Blue Light Has a Dark Side.

Man Falling Asleep in Front of Computer“Study after study has linked working the night shift and exposure to light at night to several types of cancer (breast, prostate), diabetes, heart disease, and obesity. It’s not exactly clear why nighttime light exposure seems to be so bad for us. But we do know that exposure to light suppresses the secretion of melatonin, a hormone that influences circadian rhythms, and there’s some experimental evidence (it’s very preliminary) that lower melatonin levels might explain the association with cancer.”

And here is an informative article from Scientific American in September last yearThere is now substantial research that this is a significant problem, as well as a health issue.

What can we do? Use orange to block the blue!

A simple low-tech way to reduce a lot of the blue light at night is by wearing orange sunglasses. I have friends who use them while using the computer screen at all times.

But an alternative to wearing orange glasses is to use an app for all your devices. F.lux has been available for years. And very successful it is, too. Or use Apple’s Night Shift, when it’s available.

Of course, exposure to blue light – preferably natural light – is important during the day to maintain proper circadian rhythm. It’s only blue light at night that causes the problem.

Avoid too much blue light at night by:

  • Limiting or avoiding TV, computer, and phone use after dark. If sleep is a problem for you, this drastic measure is worth a try!
  • If that isn’t possible (likely it’s not!) using orange sunglasses will reduce the blue light.
  • Installing an app like f.lux on computers and tablets will automatically reduce blue light on these devices after dark. This is my choice.
  • Dimming overhead lights or using lamps with orange bulbs at night can also help.
  • And exposing yourself to natural sunlight during the day will help keep your circadian rhythm in balance – and you’ll get a good dose of vitamin D, too. 🙂


Comments (7)

  1. coloradoleen


    This is a great article. We have a program called Flux on all of our computers. First time I noticed it, before hubby told me he added it, I was a little concerned when the color changed on my laptop. lol Another great tip, and one I need to try a lot more often, is to turn off all electronics an hour before going to bed and just read a good old fashioned paper back book.

  2. Reply

    Switch off all the lights so you can sleep properly. Our bodies are attuned to pitch darkness at night.
    Here in Singapore, there is no darkness. You can only see a couple of stars ever, because the sky is lit up by city lights. When I walk round my apartment at night, I can see easily. It’s a problem.
    Any light affects your body chemistry and causes imbalances.
    Don’t worry about the color, just skip the light, is my advice.

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