Sure, they make life easier, but could all this technology be harmful to your health? WebMD gets the experts to weigh in.
By Susan Kuchinskas
WebMD FeatureReviewed by Louise Chang, MD
The computer revolution created new ways of working, sharing information, and having fun. Our high-tech gadgets and devices may be wonderfully expansive of our intellects, but they can be hard on our bodies. And being "always on" can take a toll on your health.
Here are seven ways technology and the high-tech lifestyle may be hurting you.
1. Computer Vision Syndrome
The human eye is not adapted for staring at a single point in space for hours on end. If you log significant time in front of a computer monitor, you've probably experienced computer vision syndrome: eyestrain, tired eyes, irritation, redness, blurred vision, and double vision. Luckily, this isn't a permanent condition; but persistent strain can open the door to infection.
Working into the evening face-to-face with an illuminated monitor can play havoc with your internal clock. Replace work with exciting stuff like video games after dark, and you have an even more potent recipe for a sleepless night. One study showed that playing a game involving shooting suppressed levels of melatonin, the hormone that's involved in regulating cycles of sleep and waking.
Chilling in front of the TV is no better. Another study showed that adolescents who watched three or more hours of television per day were at a significantly elevated risk for frequent sleep problems by early adulthood.
3. Repetitive Stress Injuries
The constant tiny movements needed to maneuver a mouse or type on a keyboard can irritate tendons; swelling can press on nerves. As little as a half hour a day of computer mouse use could put you at risk for pain in your shoulder, forearm, or hand.
But repetitive stress injury, or RSI, can affect your whole body, not just the part you've overused, says Mary Barbe, PhD, a professor in the department of anatomy and cell biology at Temple University. Injured cells release substances called cytokines that travel through the bloodstream.
"If you have enough of these circulating in your bloodstream, they can be toxic to nerve cells and other cells," Barbe tells WebMD.
There's a much more direct relationship between obesity and a digital lifestyle. It comes from spending too much time sitting on your rear. It's not late-breaking news that Americans are getting fatter and that kids are packing on extra pounds at a younger age. The hours per day Americans spend glued to the tube has been trending steadily upward, according to the Nielsen Co., with households leaving the set on for an average of eight hours and 14 minutes per day during the 2006-2007 season.
"Basically, the more TV you watch, the heavier you are," Jason Mendoza, MD, MPH, tells WebMD. In addition to the sedentary activity itself, all the commercials for gooey pizza actually can make you eat more, he says.
Nowadays, screen time isn't limited to television; we may spend as much or more time using a computer for work or school. Then, for recreation, instead of going outside to shoot some hoops, we play video games. When Mendoza, assistant professor of pediatrics at Baylor College of Medicine, compared the body weights of preschoolers who used computers and those who didn't, he found the computer-using kids were tubbier. More than two hours a day parked in front of any kind of screen seems to be the tipping point, he says.
5. Hearing Damage
Even when we're out and about, we take our electronics with us, often in the form of iPods or other digital music players. It's nice to be insulated from the hurly-burly of modern life, but listening to music through headphones can increase the risk of hearing loss.
Robert E. Novak, PhD, CCC-A, has been testing the hearing of students at Purdue University, where he's head of the department of speech, language, and hearing sciences. He's seeing too many young people with older ears on younger bodies -- loss of the ability to hear high frequencies that used to occur in late middle age.
While OSHA warns employers to limit workers' exposure to noise levels above 85 decibels, Novak says people commonly listen to music through headphones at 85 to 110 decibels. "It's not just the level of the noise, it's the duration," he points out. Our ears can recover from a siren screeching past, but exposure to loud noise for hours every day can permanently destroy cells in the inner ear.
6. Risk of Life and Limb
Chatting on your cell phone makes you drive like you're drunk, says David Strayer, a professor of psychology at the University of Utah and an expert on driver distraction. Using a driving simulator, he put people with a blood alcohol level of .08 behind the wheel, and then tested them sober but using a cell phone a few days later. "The person on the cell phone was every bit as impaired," Strayer tells WebMD. You're four times more likely to have an accident with the phone glued to your ear.
Hands-free phones and voice dialing don't seem to help. It's not so much fiddling with buttons that puts you at risk, but rather that the conversation itself engages parts of your brain that would be better focused on the road. Strayer says. "It's more of an impairment because the mind is not on the road than because the hand's aren't on the wheel," he says. Because the person at the other end of the phone isn't aware of driving conditions, you get pulled into a deeper conversation than you would with someone beside you.
If gabbing on the phone makes you four times more likely to have an accident, texting doubles your risk yet again, Strayer says. "Taking your mind off the road for even a second can be very hazardous," he says, yet reading and replying to a message tends to take a few seconds. Add to that the need to hold the device steady, and it's not surprising that you're eight times more likely to crash while texting.
7. Office-Related Asthma
Your sleek, high-tech office may be a source of indoor air pollution. Some models of laser printers shoot out invisible particles into the air as they chug away. These ultra-fine particles can lodge deep in your lungs. Not every printer is a health hazard. In one study of 62 printers, 40% tested emitted particles. But only 17 printers were high-particle emitters.
So why does technology have so many harmful effects on our bodies? It may be because while traditional tools evolved over eons, technology evolves more rapidly than our understanding of how we'll use it, says Barry Katz, professor in the industrial design and graduate program in design at Stanford University.
"It may have taken 10,000 years to evolve the form of a sewing needle, or 2,500 to evolve the form of the safety pin," he says. "That gives a lot of time to work out the kinks in the system."
But modern devices, from the mouse to the ear bud, were invented from scratch. "You know about the electronics inside, but you don't know how people are going to use it," Katz says. He promises that designers are continually fine-tuning our gadgets to make them more helpful and less harmful.
Until they're perfected, though, take extra care to make sure your gizmos don't put a kink in your health.