Screen Time: How Much is Too Much?

By JEREMY LECHAN, Tufts Medical Center Staff

In 21st century America, screens dominate our lives. They are at work and at home.

We look at them when we're on the go and when we're relaxing. Most of us have at least one with us at all times, wherever we are and whatever we're doing.

But how much screen time is too much, especially for the developing minds and bodies of our kids?

"Too much screen time – time spent in front of TVs, computers, smart phones and video games - can result in an increased risk of obesity and all the negative side effects that come with it," said Mary Brown, MD, Pediatrician at Floating Hospital for Children at Tufts Medical Center. "And for older children, it also can potentially expose them to cyber bullying, sexting or even online trafficking. Poor sleep habits and inadequate sleep are also significant problems."

Effect on Sleep

According to Director of the Center for Sleep Medicine Khalid Ismail, MD, children's screen time is adversely associated with sleep outcomes, particularly difficulty falling asleep and shortened sleep duration. This may result in daytime sleepiness and fatigue that can affect performance at school.

"Screen time, especially in the 90 minutes prior to bedtime, has strong, negative effects on sleep quantity and quality," said Dr. Ismail. "The screen's light suppresses melatonin, a hormone your biologic clock needs to start the sleep process. In addition, the light exposure from the screen stimulates and tricks the brain into thinking its daytime, making it harder to fall asleep."

AAP Recommendations

The American Academy of Pediatrics (AAP) recommends no exposure to screens whatsoever for children younger than 18 months old, with only one exception: video-chatting with friends and family.

"This type of interaction for young children is much different than watching TV, as it helps promote cognitive development through social encounters with other people," said Dr. Brown. "Even educational TV shows don't offer this type of benefit for kids under a year-and-a-half old."

For children 18-to-24 months, the AAP recommends parents only allow screen time that is educational, when it can be viewed with an adult who can explain what the child is seeing.

The AAP advises that older children, ages two-to-five, experience one hour or less per day of high quality screen time that is both age-appropriate and assists in the development of cognitive skills.

"Sesame Street and other PBS shows are ideal examples of recommended screen time for this age group," said Dr. Brown. "Some apps can be good too, but no type of screen time is as beneficial as interacting with people."

The AAP says that parents of kids six and older should impose a consistent daily cap on screen time.

"It's so important for parents to set boundaries and establish technology-free, 'unplugged areas' of the home – such as the dinner table and the bedroom - starting when their children are very young," said Dr. Brown. "It's also critical for parents to be involved in supervising their kids' screen time. If parental controls are available on TVs, computers or smart phones, be sure to use them to block violent or inappropriate apps, videos, channels and websites."

Other Potential Side Effects

Too much screen time can also have adverse effects on children's eyes. Director of Pediatric Ophthalmology Mitchell Strominger, MD, points to a recent study which found that smartphone use is a risk factor for pediatric dry eye disease. Dr. Strominger has also seen a recent uptick in young patients with occipital neuralgia – headaches from the back of the head to the eye.

"This happens when the nerve that comes up from the back of the neck gets pinched, often as a result of kids having their heads down in their lap for a long period of time while on their devices," said Dr. Strominger.

And for video game players and frequent texters, hands may be at risk as well. "Gamer's thumb" is an overuse injury to the base of the thumb that often results from texting or playing video games for long periods of time.

"Excessive use of video games and cell phones can have a significant impact on children's hands," said Orthopaedist-in-Chief Charles Cassidy, MD. "Kids should take a break from video games about every twenty minutes or so to give their hands a rest and avoid gamer's thumb."

Takeaway Message

While Dr. Brown acknowledges that screens and media have their benefits, she stresses the need for parents to recognize the risks of too much screen time, especially at the expense of interactive play.

"Screens just don't promote that same type of cognitive development in kids," she said. "So parents need to be vigilant to ensure their children limit their screen time, and the screen time they do have is beneficial and constructive."

The above content is provided for educational purposes by Tufts Medical Center. It is free for educational use. For information about your own health, contact your physician. Posted May 2017.