Evidence Suggests Blue Light Inhibits Sleep Mac OS
- Evidence Suggests Blue Light Inhibits Sleep Mac Os 13
- Evidence Suggests Blue Light Inhibits Sleep Mac Os Operating System
- Evidence Suggests Blue Light Inhibits Sleep Mac Os X
Like a lot of Americans, Amalie Drury has grown very attached to her smartphone.
The 33-year-old Chicago writer checks the device multiple times a day for Facebook updates and email messages. She brings it into the bathroom when she brushes her teeth. And she often totes it to bed, 'just to check email one more time and play a few more rounds of Words With Friends.'
Since the sun is a natural source of it, our bodies have evolved to use the presence of blue light to gauge whether it’s time to sleep or wake. We need blue light but in the right amounts. Research by the CDC shows that too little blue light can prevent our body from fully waking – a problem common in certain professions, such as mine workers. For Apple News, Rumors, Reviews, Prices, and Deals, trust AppleInsider. Serving Apple product enthusiasts since 1997.
If Drury wakes up in the middle of the night, she reaches for her phone again. 'My first thought is to pick up the iPhone to see what's happening in the news,' she said. 'I'll ... sometimes read long features and not really be able to go back to sleep.'
Drury's 'terrible habits,' as she calls them, reflect those of millions who bring their phones, tablets, e-readers and laptops to bed each night, according to consumer research. The trend is causing increasing concern in the medical community based on mounting evidence that the type of light produced by our portable electronic screens can contribute to sleep loss.
Last month the American Medical Association issued a policy recognizing '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.'
Any light at night can be disruptive, researchers say, but in recent years studies have zeroed in on the particularly potent 'blue light' emitted abundantly from the energy-efficient screens of smartphones and computers as well as many energy-saving fluorescent bulbs.
Because blue light is especially prominent in daylight, our bodies associate it with daytime, which may be why exposure to blue light can make us more alert and improve our response times. It also has been shown to suppress melatonin, a hormone that helps regulate sleep and is not produced during the day.
In May 2011, Swiss researchers at the University of Basel reported that subjects who spent time at night in front of an LED computer screen, as opposed to a screen emitting a variety of colors but little blue light, experienced 'a significant suppression of the evening rise in endogenous melatonin and … sleepiness.'
Over the last decade, neuroscientists have discovered novel light-sensitive cells in the eye that detect light. These cells are separate from those we use for vision and contain a photopigment called melanopsin that is particularly sensitive to blue light. Scientists think this light-detecting mechanism, which regulates our sense of night and day and time of year, evolved before the ability to see.
'Blue light preferentially alerts the brain, suppresses the melatonin and shifts your body clock all at the same time,' said Harvard Medical School sleep researcher Steven Lockley. 'Your brain is more alert now and thinks it's daytime because we have evolved to only see bright light during the day.'
Compounding the problem, Lockley and others said, is that unlike TV (which also emits blue light), these newer electronic screens are positioned close to our faces, increasing the intensity and effects of the blue light on our brains.
'The closer you have a light source to the face, the more intense it is,' said Lockley, co-author of 'Sleep: A Very Short Introduction.' 'And the further you go away, it falls off quite quickly. So having things close to the face is much worse than having a TV that's 10 feet away.'
The researcher stressed that these types of screens are not all bad. When used during the day, they can help stabilize circadian rhythms and increase alertness and reaction time.
Increasingly, however, consumers are using devices that emit blue light well into the night. A recent poll by Rosetta marketing consultants indicated that today almost 1 in 3 Americans who use the Internet own a tablet and that 68 percent of them report taking the device to bed.
While tablet manufacturers remain generally quiet about the blue light issue — neither Barnes & Noble, which makes the Nook Simple Touch with GlowLight, nor Amazon, maker of the Kindle Fire, responded to requests for interviews — industry watchers and scientists confirm that some manufacturers are already developing new features to automatically modulate or remove blue light emissions at night.
Representatives of Apple note that blue light emissions can be reduced on the iPad by adjusting brightness and switching to white on black mode at night through the 'settings' feature.
Other companies also are working on technical solutions. In 2005, after conducting early studies on the effects of blue light on sleep, researchers at John Carroll University in Ohio formed a spinoff company called Photonic Developments to market products that can mitigate blue light exposure. These include orange-tinted glasses, screen filters and blue-light-free bulbs, all sold at LowBlueLights.com.
'We have many people talking about the problem,' said Richard Hansler, one of the scientists who developed the products, 'but I'm surprised that so few have come up with solutions for it.'
There is also a free computer program called f.lux — downloadable at stereopsis.com/flux — that reduces the levels of blue light coming from a computer screen later in the day.
Many people who use electronic media in bed told the Tribune they had trouble sleeping or suffered from insomnia, but others felt that streaming a sitcom, reading an e-book (especially in white letters on a black screen) or perusing Facebook relaxed them and could even put them to sleep.
Sheri Jacobs, who runs a marketing firm in Deerfield, is in the second group. Jacobs said she uses electronic devices mostly for entertainment and reading later in the evening, leaving email and other work-related tasks for the morning.
'I'm a great sleeper, probably because I run in the early morning and I'm exhausted by bedtime,' Jacobs said. 'I've heard about (concerns over electronic light at night) and so my approach has been to disconnect from the email at a certain point and use it for fun things like reading or watching videos.'
Dr. Alon Avidan, who directs the Neurology Clinic at UCLA, recommends good sleep habits — bright days, dark nights — to everyone but says some people are genetically much more sensitive than others to the effects of light exposure.
'Some patients will watch TV and do computer work late at night and not suffer from insomnia or other problems,' he said. 'But other people have what's called hyperarousal. They can't go to bed without reading email, and then they have a hard time shutting their mind off. Those are the patients for whom light exposure is having a greater impact and who are genetically more likely to be affected.'
He also notes that electronic media exposure is rarely the sole culprit in sleep problems.
Evidence Suggests Blue Light Inhibits Sleep Mac Os 13
'There are often many other factors involved such as stress, anxiety and sometimes restless leg syndrome,' Avidan said. 'So it's hard to say that the electronics are purely at fault, but they certainly aren't making things any better.'
While it's clear that light exposure can delay sleep initiation, it's still unclear whether it can contribute to sleeplessness in the middle of the night. Also unclear are the exact light intensities that will trigger sleep disruption and whether adolescents respond to light exposure in the same way that adults do. The AMA and others have recommended further research into this still-young field.
Drury, the late-night iPhone user, said she's intent on changing her ways 'out of courtesy to my fiance,' among other motivations.
Evidence Suggests Blue Light Inhibits Sleep Mac Os Operating System
'I have always been a pretty calm and focused person,' she said. 'But I am feeling a little adult ADD about this, and I want my brain to slow down.'
For others, even those with trouble sleeping, removing the electronic screens from the bedroom will be a harder transition. The devices have simply become part of their life.
Heaven on Seven chef Jimmy Bannos said he keeps smartphones and an iPad with him at all times, including on his bedside table next to his sleep apnea machine.
'It's for relaxation and staying in touch,' he said. 'When I wake up in the middle of the night, I'll take a look at them, check my email, see what's happening in the restaurants and even do some Internet banking. I also like to go on Facebook to see whose birthday it is and wish them a happy birthday.'
Bannos said he follows a lot of good sleep practices, including using blackout curtains, a white-noise fan and even a sleep mask. So would he ever take the next step and consider removing the blue-light devices from his bedroom?
'No,' he said, echoing the sentiments of many who don't want to give up this part of their nightly routine. 'Never.'
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It’s become a virtually unchallenged piece of conventional wisdom that exposure to blue light—the type emitted by electronic device screens—is bad for sleep. That thinking has spurred a mini-industry of innovations meant to stop those effects, like warm-toned “night mode” settings on gadgets and glasses that claim to block blue light.
But in December, a group of researchers at the University of Manchester in the U.K. published a paper in Current Biology challenging that notion. After exposing mice to lights that were different in hue but equal brightness and assessing their subsequent activity, the researchers concluded that yellow light actually seems to disturb sleep more than blue. Warm-toned light, they hypothesized, could trick the body into thinking it’s daytime, while cooler blue light more closely mimics twilight.
The study was surprising, given the widespread thinking around blue light, but it wasn’t unprecedented. Some researchers have argued that, while electronics can keep you up because of their bright lights and ability to time-suck, blue light isn’t necessarily the problem. So what’s the best way to get a full eight hours each night? Here’s what experts say about blue light.
Why is blue light thought to disrupt sleep?
Evidence Suggests Blue Light Inhibits Sleep Mac Os X
Your body is dictated by its circadian rhythms, a set of time-dependent physical, mental and behavioral shifts. The most obvious circadian rhythm is the one that drives you to be tired at night and alert during the day. This process is dependent upon melatonin, a hormone secreted when it’s dark outside. Nighttime light exposure can confuse this process, suppressing melatonin production and keeping you up longer.
Studies have suggested that blue light is an especially powerful melatonin suppressant. Melanopsin, the pigment that helps eye cells assess light brightness, is particularly sensitive to shorter, cooler wavelengths like blue light, which some research says means blue light may affect the body more dramatically than other hues. One highly cited study from 2014 showed that using a blue-light-emitting iPad before bed suppresses melatonin, while reading a traditional book does not. IPad readers started producing melatonin 1.5 hours later than usual the next day, and experienced REM sleep—the phase during which dreams occur and memories are consolidated—once they conked out, the study found.
Does the new study change that theory?
Animal studies should always be taken with a grain of salt, as they often do not translate directly to human behavior. And there are additional caveats to this particular paper, says Dr. Cathy Goldstein, a sleep specialist at Michigan Medicine. The researchers looked specifically at cones in the animals’ eyes, which detect color, instead of melanopsin, which senses light and is central to the issue of melatonin secretion.
They also kept light levels dim, regardless of color, which may not reflect the bright lights of electronics.
And finally, though mice are frequently used in sleep research, Goldstein notes that since the rodents are nocturnal, they may respond differently to light than humans do. Taken together, Goldstein says these conditions mean the study’s results apply only to a very narrow set of circumstances and metrics. “For this to get extrapolated to saying ‘blue light at night isn’t bad for you’ is a little bit of an extension,” Goldstein says.
But that doesn’t mean blue light is evil. “Blue light has become the gluten of the sleep world,” Goldstein says with a laugh. In other words, though it may be a potential trigger for health issues, its impact has been blown way out of proportion.
“We put the cart so far ahead of the horse” with blue light, agrees James Wyatt, who directs sleep disorders and sleep-wake research at Rush University Medical Center. In Wyatt’s view, recommendations around limiting blue light have far outpaced science around its effects. There is a valid scientific basis to the idea that blue light interrupts sleep, since research consistently shows that light of any kind suppresses melatonin and blue light may do so to an especially extreme degree. But Wyatt says most human research done in this field hasn’t been representative of the way the average person is exposed to blue light. That is, most experimental conditions don’t correspond to the average person’s day, and even then they often result in only tiny changes in sleep.
Take that iPad study, for example. While it did show that bedtime exposure to blue light through an iPad can suppress melatonin, Wyatt notes that people who read on their devices for hours took only 10 minutes longer to fall asleep than paper book readers. “In over 20 years of practicing sleep medicine, I have never had a patient come to me and say, ‘Hey, doc, can you help me fall asleep 10 minutes faster?'” Wyatt says.
Goldstein adds that the spectrum of light isn’t the only thing that matters—so do brightness, and duration of exposure. “You can’t just worry about spectrum alone,” she says. “You can’t have your blue light filter on, and then have your phone or your tablet at maximal brightness” and expect to drift right off with no problem.
Should I try to limit blue light exposure?
There are plenty of reasons other than sleeplessness to not spend all your time staring at screens, from possible mental health consequences to their correlation with a sedentary lifestyle. But in terms of eye health, there’s no reason to spend your time and money looking for blue-light-filtering glasses or gadgets, says Dr. Matthew Gardiner, an ophthalmologist at Massachusetts Eye and Ear. While some people report improvements in eye-strain or headaches after using these products, Gardiner says there’s no research to suggest blue light damages your eyes. “If you feel more comfortable, then that’s fine, but it does not do anything for the health of your eyes,” he says.
For sleep, Wyatt says the evidence isn’t strong enough to issue a blanket recommendation on blue light. That doesn’t necessarily mean it’s a good idea to use technology before bed—any bright light right before sleep can mess with circadian rhythms, and firing off last-minute emails is unlikely to lull you to sleep—but blue light may not be as universally bad for slumber as people think. Personal preference plays a role, too. Wyatt notes that some people feel relaxed and sleepy after watching television, while others feel wide-awake after flipping through a page-turning book.
Goldstein agrees that blue light research isn’t as conclusive as it’s often portrayed, but says there’s also no reason not to use night-mode filters on electronics if you find them helpful. Just remember to turn down the brightness and avoid hours of aimless scrolling, she says.
Finally, research is pretty definitive on the fact that a dark room is the best environment for sleep, so it’s smart to block out light sources when it’s actually time for bed. Wyatt suggests keeping your room at a cool 65° to 68° Fahrenheit, limiting intermittent noise and sticking to roughly the same sleep and wake times each day to get quality rest.