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Your smartphone is no longer just a communication device – it’s public enemy No. 1, blamed for everything from destroying family mealtimes to distracting kids from exercising. The gadgets themselves are harmless, of course. It’s the siren call of the software, beckoning us to gaze at tiny screens 24/7, that’s wreaking havoc on our vision, posture, soft tissues and sleep.

Fortunately, with a few adjustments and some moderation, it’s easy enough to avoid the physiological downsides of a smartphone habit. Here are the fixes for five potential health risks.

Eye strain

The good news: Staring at your smartphone should not cause permanent eye damage, ophthalmologists say. The bad news: Up to 40 per cent of adults, and 80 per cent of teens, suffer from eye strain, eye fatigue and dry eyes linked to smartphones and other screen time, according to a 2016 report in Optometry in Practice.

Gazing at a screen up close for long periods can cause spasms in the tiny muscles that adjust the shape of the lens, said Dr. Christine Law, an ophthalmologist and spokesperson for the Canadian Ophthalmological Society. When these muscles are overworked, “people find that they have difficulty looking far away and up close as quickly or as easily.” With prolonged screen time, she added, “We actually blink less often, so then you get the effects of dry eye,” meaning red, swollen or irritated eyes.

Children in particular tend to ignore the symptoms of dry eye or blurred vision if they’re enjoying themselves, said Law. While there’s no evidence that screen time causes myopia, she added, “current research is showing that children who spent more time outdoors, looking at things far away, are less likely to become really nearsighted as they grow older.”

The fix: Reduce screen time if possible, and take a break every 20 to 60 minutes to allow eyes to look far and wide. Remind yourself to blink often while using a phone or tablet, and use eye drops if necessary to keep eyes hydrated.

Smartphone stoop

Spending hours a day hunched over a mobile device can be a pain in the neck, not to mention the shoulders and upper back. Here’s why: When the head is in neutral position – with no bend in the neck – the pressure on the spine is 10 to 12 pounds, about the weight of your head. But when the neck bends down by just 15 degrees, the pressure increases to 27 pounds. A 45-degree tilt adds up to nearly 50 pounds, according to a 2014 study published in Surgical Technology International. Constant downward tilting of the head could lead to early wear and tear of the cervical spine, “and possibly surgeries,” wrote the paper’s author, Dr. Kenneth Hansraj, a spine surgeon in New York.

Excessive scrolling or texting, meanwhile, can overtax the soft tissues of the thumb, hand and wrist. Pain in these areas doesn’t necessarily mean you have an injury, noted Dr. Alex Scott, an associate professor of physiotherapy at the University of British Columbia. “It’s just a warning sign.” But if you keep texting through the pain, you could develop inflammation of the tendons – tendinitis – and end up wearing a splint.

The fix: “Don’t stay stuck in any one position for more than 15 minutes,” Scott said. Vary the tilt of your head, and take frequent breaks. For a more ergonomic setup, he recommends connecting a smartphone to an external keyboard whenever possible. If not, voice-activated apps can complete many smartphone tasks for you.

Sleep loss

In just six years, from 2009 to 2015, U.S. teenagers were 15 per cent more likely to report sleeping less than seven hours a night, according to a survey of 369,595 adolescents published in the journal Sleep Medicine. After ruling out factors such as homework time, TV watching and part-time jobs, researchers concluded that digital devices were the most likely culprit in teenagers’ sleep deprivation. No one has conducted similar surveys of adults, said Dr. Peter Reiner, a professor of neuroethics at UBC, “but I think the data can be generalized.”

Scientists theorize that the blue light from backlit screens interferes with natural production of melatonin, the hormone involved in the body’s sleep-wake cycle. In a 2015 study from Harvard University, 12 men and women who read from screens before bed showed lower blood levels of melatonin, took longer to fall asleep and were groggier in the morning, compared to when they read from a printed book, the study authors wrote. “We found that the use of portable light-emitting devices immediately before bedtime has biological effects that may perpetuate sleep deficiency and disrupt circadian rhythms.”

Studies have linked chronic sleep loss with higher rates of colon and breast cancers, Alzheimer’s disease, obesity and type 2 diabetes.

The fix: Activate the “night time” mode on your smartphone to adjust the blue light to a warmer hue, Reiner said: “It’s one of the first things that I recommend everybody does.” The next step: Ban your phone from the bedroom to avoid temptation in the middle of the night. You might claim you need it as an alarm clock, “but that’s a terrible excuse,” said Reiner, “because for $10 you can buy yourself an alarm clock and get a good night’s sleep.”

Bacterial infection

Can you get the flu from your smartphone? Hypothetically, yes. Most of us check our phones in between touching germ-infested elevator buttons, transit handrails and shopping carts. The average smartphone tests positive for a range of bacteria, from E. coli – the bug that causes food poisoning – to influenza viruses, studies have shown.

Handwashing is no defence when these germs are on our phones. In a 2012 study in the International Journal of Infection Control, researchers asked health-care workers to make a call on their mobile phones after using hand sanitizers (cell cultures confirmed the absence of harmful bacteria on their hands). But immediately after touching their phones, 94 per cent of participants showed bacterial contamination on their hands.

The fix: Microbiologists recommend wiping down smartphones with a damp microfibre cloth at least once a day. Disinfectant wipes made specifically for electronics may help neutralize more tenacious bacteria, such as flu viruses and Clostridium difficile. As for using your smartphone in the bathroom, just stop.

Cellphone radiation

Researchers continue to investigate the possibility that exposure to radio-frequency radiation could cause brain tumours. So far, results from studies dating back to the 1980s have been reassuring. According to reviews conducted by Canadian experts in 2014 and 2016, studies of radio-frequency radiation “have not provided results that could reasonably support a link between cancers and other illnesses,” said professor Mary McBride of the BC Cancer Agency.

In February, the National Toxicology Program at the U.S. National Institutes of Health released two major reports that found no increase in illness or death in rodents subjected to the equivalent of much higher radio-frequency radiation exposure than humans receive. The only abnormality was an increased risk of a slow-growing benign tumour in the brain and heart of male rats, but not females or mice. The authors concluded that the results could not be applied to humans. Research continues in a European study named COSMOS and a study involving children, called MOBI-KIDS.

In Canada, rates of cancerous brain tumours have remained “effectively flat” over the past 25 years, at about 0.3 per cent for both men and women, McBride said.

The fix: None needed, based on the lack of evidence of harm. Nevertheless, Health Canada offers precautionary recommendations, particularly for children, such as spending less time on cellphones and switching them off when not in use. Keeping phones away from the body and using hands-free options can also help reduce exposure to radio-frequency radiation, said McBride.

Editor’s note: An earlier version of this story incorrectly referred to Mary McBride as a Dr. In fact, she is a professor.

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