DR. DAVID WONG: Watch out for eye strain
Dear Dr. Wong: I worry about my granddaughter. The other day, I saw her lying on the couch watching a video on her mom’s phone, holding it inches from her eyes. My daughter was sitting next browsing social media on a tablet. I was going to say something, but I didn’t. When I use the computer, my eyes get tired after a while. How can a young person put the screen so close to her eyes without hurting herself? I wonder if there are any recommendations for children regarding screen safety.
Answer: I share your concern about how your granddaughter used the phone to watch a video. I’ve seen that too, kids using smartphones for long periods of time, scrolling through social media or watching videos. No doubt it will strain their eyes. They continue because they are interested in the content or bored by the things around them.
These screens started with computers decades ago. The monitor’s black screen with green letters and cursor has been replaced with a white screen and multicolored pages. When we spend hours with our eyes fixed on the monitor, the problem is inevitable. People have complained of blurred vision, eye pain, dry eyes, and headaches. This digital eye strain has also been called computer vision syndrome.
It has been shown that when we work with screens, our eyes don’t blink as often as they should. Blinking deposits a teardrop layer on the conjunctiva, the outermost layer of cells that protects the front part of our eyes. This thin layer of tearing hydrates the conjunctiva and keeps it healthy. When it dries, our eyes get irritated.
Our eyes can focus on things both near and far. This is done by a group of small muscles inside the eye that alter the thickness of our lens; there is a lens inside each eye. As we continue to focus on any screen, these muscles must continue to adjust to focus on the words and other items on the screen. Over time, these muscles get tired; this is the cause of eye strain that many experience after using the screen for a while.
There’s a 20-20-20 rule: stop focusing on a screen every 20 minutes, look at something at least 20 feet away for 20 seconds, and blink 20 times. Another suggestion is to take a 10-minute break after every hour of screen use, whether for work or entertainment. This allows the eye muscles to relax and reduce eye fatigue, while keeping the conjunctiva moist.
Other strategies include keeping the screen at least an arm’s length from the eyes and keeping the surrounding dark. If the environment is bright, the screen naturally becomes brighter; it will make your eyes more tired. Move the screen so that the light does not shine directly on the screen.
The pandemic has forced children to take online classes, staring even more at screens. Research has also shown that children have more screen time for entertainment during the pandemic due to isolation. It’s even more important for parents to find other activities that their kids enjoy, so they don’t use screens all the time.
Smartphones have smaller screens than computer screens and tablets. It’s natural for them to hold them closer, which leads to more eye strain than larger screens. In recent decades, the number of North American children with nearsightedness (myopia) has doubled.
In many parts of Asia, the vast majority of young people are myopic. This is partly due to genetics and partly due to the increase in indoor activities for education as well as entertainment.
Outdoor activities are important for the normal development of children’s eyes.
In addition, children should have a vision test once a year. They can’t tell when things are blurry; they assume it’s normal. The vision test can detect myopia and other problems early and prevent deterioration.
Finally, it is important to stop all screens one hour before bedtime because they can affect sleep. It is better for children to read a book in bed instead of using screens. I also recommend that parents remove all electronic devices, including televisions, video games, tablets, and phones, from children’s bedrooms at night. It is better to have an alarm clock instead of using the alarm function of the phone.
Dr. David Wong is a retired Summerside pediatrician and recipient of the 2012 Distinguished Community Pediatrician Award from the Canadian Pediatric Society. His columns appear in The Guardian on the last Tuesday of each month. You can see a collection of his previous columns at askdrwong.ca. If you have a question for Dr. Wong, mail it to Prince County Hospital, 65 Roy Boates Ave., Summerside, PEI, C1N 2A9.