It seems like children know how to operate tablets, smartphones, and computers almost from birth.

But those mesmerizing screens expose them to a number of long-term health threats.

The American Optometric Association’s (AOA) 2015 American Eye-Q^® survey found that 41 percent of parents say their kids spend three or more hours per day on digital devices. It also found that 66 percent of kids have their own smartphone or tablet.

Too much screen time can result in digital eyestrain, which can include burning, itchy, or tired eyes. Headaches, fatigue, blurred or double vision, loss of focus, and head and neck pain are other threats for children using screens too often and too long. 

“The short-term effect of digital eyestrain is not cumulative,” Dr. Tina McCarty, an optometrist from Minnesota and member of the AOA Public Policy Committee, told Healthline. “The eyes will get better when you give them a break and/or wear the proper eyewear in the form of lenses and coatings based on the patient’s specific needs to minimize eyestrain.”

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The Eyes Have Had It

Electronic devices also give off high-energy, short-wavelength blue and violet light.

This light can affect vision and cause premature aging of the eyes. Early research shows that overexposure to blue light can contribute to eyestrain and discomfort. It also can trigger serious conditions later in life such as age-related macular degeneration, which can lead to blindness.

“We know that damage from UV light is cumulative in the eye and that a lifetime of protection is critical in protecting from certain eye-related disease as we age,” said McCarty. “Blue light is very near UV light in wavelength and energy and therefore there is concern for cumulative damage over a lifetime of exposure.”

The younger eye typically has a keen ability to accommodate and focus on close objects as the natural lens of the eye is smaller and clearer, she said. However, the accompanying blue light is more easily transmitted to the retina, potentially causing damage. 

Blue light can also interrupt sleep patterns and circadian rhythms when children view screens close to bedtime.

Toddlers may still be settling into healthy sleep patterns, so McCarty says it’s even more critical for blue-light exposure to be eliminated long before these children go to bed.

She said there is “increasing evidence to support a link between blue light exposure and macular degeneration.” Long-term effects of blue light exposure are still being studied, though.

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Protecting Children’s Eyes

To protect their eyes and vision, children should take frequent visual breaks. Use the 20-20-20 rule: Take a 20-second break every 20 minutes and look at something 20 feet away.

As far as how many hours a day your child should be allowed to use a digital device, McCarty said there’s no standard for what’s safe. Taking breaks is the best way to protect their eyes.

Children should also have eye exams each year as their eyes are still developing between the ages of 5 and 13.

“Be sure that children have had an annual comprehensive eye exam to find out if the digital devices are causing any eye problems,” McCarty said.

If there’s a problem, it’s easier to correct when detected early. Vision and eye health can also affect a child’s learning capacity.

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Careful How Kids Sit, Too

It’s not only the screen that can cause problems. The position a child assumes while using an electronic device is also important.

Dr. Peter Ottone, a chiropractor from New Jersey, said that poor posture from computer and tablet usage has become epidemic. 

“This problem has always affected adults but increasingly is having an effect on children's spines and postures as well. With increasing computer usage for school as well as for leisure enjoyment, the time kids are spending on computers is ever increasing,” he told Healthline.

The slouched posture students often use when at a computer workstation increases pressure on the spinal muscles, ligaments, nerves, and disks. This increases the susceptibility for neck pain, back pain, and headaches, Ottone said.

“I have noticed a large increase in teen and preteen kids with these complaints enter my office over the past several years,” Ottone said.

He reports also seeing a lot of cases of “text neck” from extensive mobile phone usage.

For computers at desks, Ottone said that the top of a computer screen should be at or only slightly below eye level. The chair should allow the user to be as close to the mouse/keyboard as possible so as to eliminate reaching. The feet should be flat on the floor or placed upon a raised surface.

When a child uses a tablet, the same principles apply, but a pillow should go under the forearms to raise the tablet to the appropriate level so the child doesn't have to look down at the screen.

“This will also relieve some pressure from the wrists, eliminating possible carpal tunnel and tendinitis conditions,” Ottone said.

“Parents should take the time to make sure their kids are using proper ergonomics with all these devices and encourage kids to take regular breaks from these postures to help reduce the overuse syndrome risks,” he added. 

Source : http://www.healthline.com/health-news/screen-time-hurts-more-than-kids-eyes-101215#5