Screen time for kids: How it affects child development
Children and technology are practically inseparable these days. Whether for educational purposes or just fun, children are spending a good portion of their day on "screen time" — staring at the LED screens of computers, tablets, smartphones and other digital devices.
According to Common Sense Media, children under age 8 now spend more than two hours a day with screen media. For 8- to 10-year-olds, screen time triples to six hours a day. And it's not unusual for kids in school to spend up to nine hours per day looking at digital displays.
If you're wondering if all this screen time might cause problems for your child's eyes and vision, the short answer is: "Yes, it does."
Risks associated with too much screen time
Children who spend multiple hours staring at digital devices are at risk of developing these vision-related problems:
Computer vision syndrome
Computer vision syndrome — also called digital eye strain — is a condition that's caused by visual stress from extended screen time.
Computer vision syndrome has a combination of symptoms, including: fluctuating vision, tired eyes, dry eyes, headache and fatigue. Other non-visual symptoms of computer vision syndrome include neck, back and shoulder pain.
When using a computer or digital device for prolonged periods, it's common to start slouching inward, rounding the back and shoulders, and then tilt the head back and jut the chin forward. This unnatural (and unhealthy) posture — called "turtling" — leads to many of the non-visual symptoms of computer vision syndrome.
Vision researchers believe increased screen time among children is a significant risk factor for the development and progression of nearsightedness (myopia). The prevalence of myopia has grown significantly in the last few decades and this trend coincides with the increased use of computers and digital devices by children.
Increased exposure to blue light
High-energy visible light called blue light is emitted by the LED screens of computers, tablets, smartphones and other digital devices. Although the most significant source of blue light exposure is natural sunlight, many researchers and eye doctors are concerned that the added blue light exposure from computers and digital devices might increase a person's risk of age-related eye diseases like macular degeneration later in life.
What to do
It's not realistic to think that children will stop using modern technology. But there are some easy things you can do to decrease your child's risk of eye and vision problems from prolonged use of computers and digital devices:
Encourage frequent visual breaks
One of the best things you can do to reduce your child's risk of digital eye strain is to get them to follow the "20-20-20" rule: Every 20 minutes, take your eyes off your screen and look at something that's at least 20 feet away for at least 20 seconds.
This simple task relaxes the focusing and eye alignment muscles, reducing the risk of many of the symptoms of digital eye strain.
The 20-20-20 rule also might decrease the risk of myopia progression. Some research suggests focusing fatigue may be associated with the onset and worsening of myopia. Taking frequent breaks from staring at digital screens helps reduce this fatigue.
Encourage frequent posture checks
The time taken to follow the 20-20-20 rule is also a good time to sit up straight and realign the head, neck and shoulders. Moving the head slowly to the right and left and also up and down can relieve strained muscles and reduce fatigue.
If it's possible, getting up to walk and stretch the entire body also is a good idea to reduce the risk of non-visual symptoms of computer vision syndrome. [Read more about computer ergonomics.]
Protect their eyes from blue light
Currently, no one knows for sure how damaging the added exposure to blue light emitted by computer screens and digital devices might be to a child's eyes over time. It may take researchers decades to sort that out.
In the meantime, it's prudent to protect your child's eye from blue light from both sunlight and digital devices.
Outdoors, polarised sunglasses offer the best protection from glare and blue light, blocking roughly 90 percent or more of the sun's harmful blue light.
For indoor and outdoor wear, photochromic lenses such as Transitions lenses (Essilor), are an excellent choice.
For indoor wear, eyeglass lenses with an integrated blue light filter are a good choice.
Finally, certain anti-reflective coatings can help eyeglass lenses filter blue light.
Establish media-free times
It's a great idea to establish media-free times each day to break your child's fixation on digital devices, reduce eye fatigue, and limit blue light exposure. Use this time to connect as a family.
Schedule annual eye exams
Finally, schedule a comprehensive eye exam for your children prior to the start of every school year. In addition to making sure your child's eyes are healthy and seeing well, your eye doctor can perform special tests and provide specific suggestions to reduce the risk and symptoms of computer eye strain.
Children and technology are the future. Taking these simple measures can go a long way toward keeping your tech-savvy child seeing clearly and comfortably for years to come.
Page published in June 2019
Page updated in September 2020