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Blue light at night?

When Apple announced a new feature called Night Shift as part of their next software update, it added to the general awareness of the effects of light on our health. Night Shift 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 electricity and light bulbs, people used sunshine for light and only natural light-sources like candles, campfires and lanterns after dark. These are all orange-based lights. Now, artificial light from computers, TVs, tablets and mobile phones, has extended exposure to artificial light even more. All of these 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 show 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 useful article from Harvard Health Publishing which explains quite simply, what blue light is, and gives some tips on protecting yourself from blue light at night.  Read more here: Blue Light Has a Dark Side.

“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.”

Here are some informative articles:  Why is Blue Light Bad for Your Sleep? from Scientific American  with substantial evidence that this is a significant problem, as well as a health issue. And Blue LEDs Light Up Your Brain.

What can you 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.

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.

Tips to avoid blue light at night:

  • Limit or avoid 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!) use orange sunglasses to reduce the blue light.
  • Install an app like f.lux on computers and tablets to automatically reduce blue light on these devices after dark. This is my choice.
  • Dim overhead lights or using lamps with orange bulbs at night can also help.
  • And expose yourself to natural sunlight during the day to help keep your circadian rhythm in balance – and you’ll get a good dose of vitamin D, too.

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