Is blue light disrupting your sleep?

Exposure to blue light at night could be disrupting your sleep.

Did you know that blue light from smartphones and computers could be holding you back from a good night’s sleep? Luckily, there are several remedies at hand.

By Beth Wallace

There’s no denying that modern technology plays a large (and welcome) part in our daily lives. Smartphones, computers, tablets, televisions and energy-efficient lighting allow us to work and play around the clock. However, researchers report they may also be affecting your sleep.

The dark side of light 

All these devices emit blue light: a high-energy short wavelength of visible light that can penetrate all the way to the back of the eye. Exposure to blue light during the day is perfectly safe – even essential for optimal physical and mental function – but it can have negative impacts at night.

According to Karen Makin, optometric services manager at Bupa Optical, our bodies simply aren’t equipped to handle exposure to blue light at night. 

“If you think back to the caveman days, the only blue light we were exposed to came from the sun,” she says. “People were awake during the day and when night fell, it was time to go to sleep.”

This pattern is known as the circadian rhythm and it controls the timing of many physiological processes, such as sleeping, brain activity and hormone production. This includes the release of melatonin, a hormone that encourages sleep.

“Our circadian rhythm suppresses the production of melatonin during the day, when light is present, then increases production when the sun goes away,” Makin explains. 

“But these days, we’re exposed to blue light in an artificial environment. This can change the production patterns of melatonin, which can lead to sleeping difficulties and daytime drowsiness.”

Extensive research has been undertaken on the effects of blue light. One study compared the sleep habits of people reading an e-book before bed with those reading a regular book. It found that the e-book group experienced suppressed levels of melatonin; took 10 minutes longer to fall asleep than the regular book-reading group; and felt drowsy the next morning.

Another study revealed that exposure to regular levels of room light (rather than dim light) during the night suppresses melatonin production by around 85 per cent.

How to reduce blue light exposure

While the obvious solution is to switch off blue light-emitting devices at night, or at least an hour before bed, Makin says this isn’t always realistic. 

“In reality, we look at these devices in the day and at night,” she says.

A more feasible option, Makin continues, is to wear glasses coated with a blue-light filter. 

“The coating blocks or absorbs the blue light at the lens surface, so it doesn’t pass through to the eye itself,” she explains. “It doesn’t block all blue light, but it does block a significant portion, which helps to keep our bodies in their natural rhythm.”

There are also apps you can install on your digital devices to filter out blue light. Programs such as f.lux and Twilight adjust the colour display of your smartphone, tablet or computer to warmer tones. 

As for lighting your home, it’s best to replace bright, cool lights with warm bulbs and use red night-lights, as they have the least impact on your melatonin production.

Finally, whenever possible, switch off your devices at night – your sleep and overall wellbeing will be the winners.

Blue-light filters on glasses

A blue-light filter is a coating applied to lenses to reduce the amount of blue light your eyes absorb. The filter has a slight bluish bloom but the lens is clear, so the glasses can be worn during the day, as well as at night.

Exclusive special offer for CPA Australia members!

CPA members who purchase a prescription multi-coat lens (clear or tinted) from Bupa Optical will receive a free blue-light coating filter.* Get a quote online at

Offer ends 13 August 2017. 

* Terms and conditions apply

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