The Effects of Too Much Screen Time on Children’s Vision

By Dr. Rahul Bhola, pediatric ophthalmologist at CHOC

Technology has become an integral part of our daily lives. As we become increasingly more reliant on and absorbed in technology, many children are exposed to smart devices at less than 5 years of age. These devices have also become an integral teaching tool in classrooms—more than half of teachers in the United States use smart devices in elementary school. According to the U.S. Department of Education, 97 percent of classrooms in the U.S. have at least one computer. School screen time coupled with at-home smart device usage can on average expose a student aged 8-18 years to media for more than ten hours a day.

As children’s exposure to screen time rises, many parents wonder how harmful excessive exposure to electronic media can be. While on one hand, an early exposure to technology might prepare children for future careers in technology-related fields, or jobs that require mastery of technology as a fundamental key to success. On the other hand, children overly immersed in this technology and not otherwise challenged can become socially stunted and ridden with health-related issues due to decreased physical activity.

One of the biggest health issues related to smart devices are vision related. A recent study by the National Eye Institute found that the frequency of myopia, also known as near-sightedness, has jumped exponentially in Americans over the last few decades. Two clear reasons for this spike in myopia are an increased amount of time spent looking at things up close and also a lack of outdoor activities. Focusing on things too close to the eyes for a prolonged period puts excessive strain on the eyes and has been found to hasten the progression of myopia. Although genetic risks of myopia cannot be modified, limiting the amount of strain on eyes by avoiding excessive time spent looking at things up close can minimize environmental risk factors. It is imperative to prevent prolonged exposure of up-close work (such as reading) in children by allowing small breaks (during prolonged reading sessions, for example).

The American Academy of Pediatrics (AAP) recently revised the recommendations for screen time in childhood.

• 18 months and younger: no screen time is still best. The exception is live video chat with family and friends.
• 18 months to 2 years: limit screen time and avoid solo use. Choose high-quality programming, and watch with kids to ensure understanding.
• 2 to 5 years: limit screen time to an hour a day. Parents should watch as well to ensure understanding and application to their world.
• 6 or older: place consistent limits on the time spent and types of media. Don’t let screen time affect sleep, exercise or other behaviors.

A separate study recently found that excessive screen time usage in adolescents was associated with development of acute onset esotropia, or crossing of the eyes, and that limiting usage of these gadgets decreased the degree of eye crossing in these patients. A portion of the patients in this study had to undergo surgery to correct esotropia.

Excessive screen time can also lead to “Computer Vision Syndrome” which is a combination of headaches, eye strain, fatigue, blurry vision for distance, and excessive dry eyes. There’s a number of things you can do to help avoid these symptoms:

• Check the ergonomics of the workstation. Placing the screens 20 to 28 inches away from the child’s eyes and aligning the top of the screen at eye level so that the children look down at the screen while they work.
• Restrict entertainment-related screen time to two hours or less a day
• Practice the 20-20-20 rule: After every 20 minutes of screen time, take a 20-second break and look 20 feet away.
• Remind children to blink regularly to avoid excessive dry eyes.

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