Before the days of the smartphone and the consumer tablet, many would wind down in bed with a book, where the soft glow of a bedside lamp illuminating the yellowing pages lulled folks hurriedly to sleep. Bright e-books and tablets, however, seem to be having the opposite effect, according to Professor Shantha Rajaratnam from Monash University's School of Psychology and Psychiatry.
Rajaratnam recently told ABC News Australia that the light emitted from tablets, smartphones, laptops and other electronic devices is sufficient to delay the timing of the body’s circadian clock, which regulates our sleeping habits. Emitting 30 to 50 lux, these devices can also suppress the production of melatonin, a hormone that promotes sleep in humans.
Brightness, color and distance all affect the resulting impact on sleep. Specifically, bright blue light held close to the face is the most disruptive. Unfortunately, this precisely describes the practice of reading an e-book or browsing the Web in bed.
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Most if not all electronic devices emit short wavelength (blue) light, which has been proven to keep people up late. Small and portable, these devices are easily used in bed, and can delay sleep by nearly an hour if used within a couple of hours of bedtime.
"We think that the advent of electric lighting has significantly impacted upon sleep-wake patterns, but with the proliferation of electronic devices that emit light we are expecting that these problems will increase," said Rajatnam.
There are other effects in play as well, including mental overstimulation and the lack of a cognitive boundary distinguishing a place for sleep and a place for study/work/socializing.
"Superimpose on top of that using a lot of electronic devices, then you end up with almost the perfect storm for a sleep problem to develop," said Dr. Amanda Gamble from Sydney's Woolcock Insomnia Clinic, supporting Professor Rajaratnam’s assertions.
This is in line with the findings of the American Medical Association's Council on Science and Public Health, which has also found a relationship between night-time exposure to blue light and sleep disorders.
"[The AMA] 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," noted a 2012 AMA report.
The obvious solution is to either turn the brightness way down to reduce the effect (albeit only partially), or to turn the device off completely at least one hour (preferably two) before bed time, eliminating the problem altogether. For many, the latter solution is undesirable at best, and laughably impossible at worst.
Perhaps software, like f.lux for Windows, can gain some traction here. f.lux is a desktop application that makes the color of your computer’s display adapt to the time of day, slowly shifting from a bright, short-waved bluish hue in the morning, to a dim, long-waved reddish hue in the evening. Taking your location and interior lighting setup into account, f.lux adjusts your display settings to suit your particular environment, reducing eye strain and insomnia.
A similar app for iOS and Android displays can certainly go a long way toward solving this problem for nighttime tablet and smartphone users. Until then, nighttime electronics users will have to weigh their desire for constant connectivity against the weight of their eyelids.
Edited by Rachel Ramsey