There are many reasons to set limits on your child’s screen time: To encourage outdoor play and healthy activity, to foster healthy sleep habits, and to promote in-person social relationships. Eye health is another.
Ayesha Malik, OD, pediatric optometrist at Children’s Hospital of Philadelphia (CHOP), helps us understand the risks of too much screen time for children’s vision, and what parents can do to help their kids adopt healthy habits.
Eye problems caused by excessive screen time
Many parents ask if looking at screens can seriously damage your eyes. Here are some of the ways — some to be expected, others more surprising — screen time can affect kids’ eyes:
Too much time indoors can lead to nearsightedness
The first problem is that screen time keeps children indoors. “Exposure to natural daylight is critical to developing eyes,” says Malik. “Kids need time playing outside for their health, but also for their eyes.”
Studies have found that children who spend more time indoors are more likely to develop nearsightedness (myopia). The exact cause isn’t yet known, but researchers believe that UV light (providing the eyes are protected from intense sunlight) plays an important role in healthy eye development. The rate of nearsightedness in children has increased dramatically in the past 30 years.
The second problem comes from the intensity with which kids focus on screen activity. “Our eyes need breaks from close-up focus,” says Malik, “and children can lose track of time when they become absorbed.”
Eyes get tired with prolonged close-focus attention, especially when the lighting around the screen causes glare and extra eye strain.
Dry and irritated eyes
Long stretches of screen time also cause the eyes to get dry and irritated. Studies show that people of all ages blink far less often when concentrating on a screen, which in turn causes the eyes to dry out. A clear and stable tear film on the surface of the eye is essential for clear vision. The problem can be worse for children who look up at a screen that is positioned for adult use.
Loss of focus flexibility
When their eyes stay focused close-up for long periods, children can also find it difficult to adjust to distance vision. That’s generally a short-term problem, and the eyes adjust back to their normal flexibility within a few hours or at most a few days.
Beyond the eyes: Impact on sleep
The other problem with screen time for kids is its effect on sleep. Research shows that the blue light from computer and device screens, when used in the evening, alters the brain’s sleep rhythms. The brain reads the screen light as “daytime” and shifts the body’s circadian rhythm. The exciting content of many video games and movies can also wind a child up when they should be winding down for bed or for a nap.
Set clear limits on screen time
In her CHOP Health Tip article, “Is Screen Time Making Our Kids Unhappy,” psychologist Katherine Dahlsgaard, PhD, reviews the mental health impact of excessive screen time and offers advice for setting limits, summarized here:
- Set a limit on daily screen time. Make it clear to your kids and stick to it.
- Encourage your child to spend some of that screen-free time outdoors while it is still light.
- Establish screen-free zones: no smartphone use for anyone in the family in the car, for example, at restaurants, or at the dinner table.
- No screens in the bedroom when it is time for bed. No exceptions.
- Model moderate screen use as a parent. Show your children, with your own behavior, how to live a rich, varied and healthy life where all habits are practiced in moderation.
Help your child practice good eye habits
Dr. Malik encourages parents to teach their children the 20-20-20 rule when using a computer or other screen device. Every 20 minutes, look away from the screen for 20 seconds and focus on something at least 20 feet away. That’s a good practice for adults to follow, as well. A timer can help your child remember. Or install a software program that turns the screen off automatically at set times.
Make sure the screen is positioned so that your child looks slightly down at it, not up. And adjust lighting to eliminate glare on the screen.
For more helpful information, Dr. Malik recommends this resource from the American Academy of Pediatrics: Give Your Child’s Eyes a Screen-Time Break: Here’s Why.
Have your child’s eyes examined
Make regular eye exams a part of your child’s healthcare schedule. You may be able to tell if your child’s eyes are tired or irritated, but it’s harder to tell if they are developing a vision problem. Only a comprehensive eye exam, by an eye doctor who specializes in children (a pediatric ophthalmologist or optometrist), can reliably tell you that.