Published on in Health Tip of the Week
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.
But with more and more of our lives lived in front of screens – whether it’s for work, school, entertainment, socialization, or exercise – how can parents set realistic limits and guidelines for their families?
Ayesha Malik, OD, pediatric optometrist at Children’s Hospital of Philadelphia (CHOP), helps us understand the risks of too much screen time on children’s vision, and what parents can do to help their kids practice healthy habits when they are using screens.
Eye problems caused by excessive screen time
Here are some of the ways screen time can affect kids’ eyes.
Eye fatigue — called asthenopia — is characterized by eye discomfort, dimness of vision and headache. Asthenopia can be caused by overuse of the eye, for example during a period of prolonged focus on a screen. Any glare on the screen can further strain the eyes.
Children with eye fatigue may complain of headaches, eye pain, or feeling tired, headaches. They may lose interest in tasks such as reading.
Another issue is that kids focus so intensely on their screens. This prolonged close-focus attention adds to fatigue. “Our eyes need breaks from close-up focus,” says Dr. Malik. “Children can lose track of time when they become absorbed.”
Dry and irritated eyes
The eyes can also get dry and irritated during long stretches of screen use. 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 eye surface is essential for clear vision. This problem can be worse for children who may have to look up at a screen that’s positioned for adult use.
Loss of focus flexibility
When children’s eyes stay focused close-up for long periods, they can find it difficult to adjust to distance vision later. Generally, that’s a short-term problem, and the eyes adjust back to their normal flexibility.
Kids who are on screens are typically 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 process is still being studied, but researchers believe UV light (as long as 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.
Beyond the eyes: impact on sleep and overall health
Screen time can also disturb kids’ sleep. First of all, the exciting content of many video games and movies can wind a child up when they should be winding down for bed or a nap.
Second, research shows that when computers and similar devices are used in the evening, the blue light they emit alters the brain’s sleep rhythms. The brain reads the screen light as “daytime” and shifts the body’s circadian rhythm.
The American Academy of Ophthalmology (AAO) contends there is currently no scientific evidence that demonstrates blue light from electronic devices is harmful or damaging to one’s eyes. Therefore, the AAO does not support the use of "blue light blocking" lenses.
A better strategy is to practice consistent, healthy habits to protect your child’s eyes during screen time. And when it comes to sleep, the best thing you can do is limit screen time, particularly in the hours before bedtime. Aim for no devices or screens for one hour before bedtime.
Help your child practice good eye habits
Most families can’t — and don’t want to — completely remove screened devices from their children’s lives. They’re part of living in the modern world. What you can do is protect your child’s eyes by teaching them healthy screen time habits.
The 20-20-20-2 rule
Since focusing on a “near task” — such as reading, writing or staring at a screen — increases the demand on eyes’ microscopic focusing system, eyes need a break to reset their focusing systems. Use the “20-20-20-2 rule.” During any concentrated visual task, encourage your child to break focus every 20 minutes, focus on something at least 20 feet away for 20 seconds, and blink 20 times. This allows the eyes to relax and to return to their natural position and baseline settings. (Adults should use this trick too!)
Kids aren’t always the best judge of time, especially when they’re engrossed in a game or movie, so consider using a timer to encourage those breaks.
The final “2” is a recommendation for two hours of outdoor play each day to stimulate the healthy development of the focusing system of children's eyes and ward off nearsightedness.
Screen size and distance
The smaller and closer a screen is, the harder your child’s eyes must work to focus on it. If possible, encourage your child to work on a larger screen, such as a laptop or desktop computer, rather than a small phone screen.
Dr. Malik suggests positioning screens at least an arm’s length away to minimize eye strain. The screen should be positioned so your child looks slightly down at it, not up. Consider following the 1-2-10 rule when it comes to screen positioning: Hold phones 1 foot away; sit 2 feet away from laptops and desktops; and encourage children to sit 10 feet away from the television.
The more reflection on your child’s computer screen, the harder their eyes must work. Lower the brightness settings on your child’s computer and other devices (there is often a setting that will do this automatically) and watch for glare on the screen to ensure comfortable viewing.
Have your child’s eyes examined
Make regular eye exams part of your child’s routine healthcare schedule. “Your child’s vision is a rapidly developing sense,” says Dr. Malik. “It deserves screening for problems and timely treatment to ensure best outcomes.”
Make sure at minimum your child is getting either the annual vision screening provided at school, or a vision screening at your pediatrician’s office during your child’s next well check.
Even if your child has a normal vision screening, they can still be at risk of asthenopia or other eye problems. If your child complains of ongoing headaches, dry or irritated eyes, or eye pain, it’s important to schedule a comprehensive eye exam with a pediatric ophthalmologist or optometrist. Unlike vision screenings, comprehensive eye exams evaluate not only the focusing system of the eye but its structure and overall health, checking for any underlying problems that may manifest during periods of high stress.
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.
Contributed by: Ayesha Malik, OD