screen time, close work and myopia

Use of digital devices is increasingly important for schooling, and screen time can be beneficial when balanced well with other activities. Spending too much time on screens is a concern for parents as excessive use can impact development of good vision as well as physical and mental health outcomes.

Children exposed to screens before age 3 are more likely to have developed myopia by pre-school age. There is an increasing volume of research indicating the link between screen time and myopia development in children and teenagers, although the negative impacts seems to be greatest in children under 10, at this crucial stage of visual development.

Screen time in children and teenagers has also been linked to development of dry eyes and digital eyestrain, which can cause significant symptoms of uncomfortable eyes, blurred vision, headache and red eyes. 

Are screens different to books?

Children and adults appear to hold screens closer than books and print material. This increases the visual demand on the eyes' focussing system. Research has shown that children who read or wrIte at a distance closer than 20cm showed faster progression, or worsening, of their myopia. This same impact occurred when reading for more than 45 minutes without a break

Screen time recommendations

When it comes to healthy childhood development in general, the following recommendations have been put forward by the World Health Organisation, Australian Government Dept of Health and the American Academy of Pediatrics.

• Children under two years of age should have no screen time. Watching a screen at a young age can limit time for active play and learning, reduce opportunities for language development, negatively influence their attention skills and affect the development of the full range of eye movement. The exception to this is video-chatting with family, which can encourage language and social development.

• Children aged 2-4 years should have a maximum of 1 hour of screen time per day, ideally co-watching with a parent. Co-watching, like reading a book together, can make screen time useful for language development and learning. In this age group, excessive screen time has been associated with less active, outdoor and creative play; slower development of language skills; poor social skills and an increased risk of being overweight.

• Children of school age (5-17 years) should be limited to 2 hours of sedentary, recreational screen time per day. Break up long periods of sitting as often as possible, and when using screen-based electronic media, positive social interactions and experiences are encouraged. Reducing screen time before bed and removing screens from the bedroom where possible can be important for healthy sleep habits.

Three easy rules for indoor time

There are three key rules for the childhood visual environment – indoors, which are important for both reducing the risk of a child developing myopia as well as reducing the risk of fast progression, or worsening, once a child has myopia.

1. The elbow rule: keep an elbow-to-hand distance away from books and screens to avoid them being too close to the eyes.
2. The 20/20 rule: take regular breaks from reading to reduce demand on the visual system.
3. The two-hour rule: try to limit leisure screen time (outside of school work) to two hours per day in school-aged children.

THE ELBOW RULE is where your child should try to keep an elbow-to-wrist distance between anything they are viewing up close, and their eyes. Try it yourself, and show them at home – make a fist, put it next to your eyes, and where your elbow sits is the closest any screen or book should get to your eyes when reading. 

THE 20/20 RULE is where you child aims to take a break from reading every 20 minutes, for 20 seconds. He or she should look across the room for that 20 seconds, to relax the focussing muscles in the eyes before recommencing reading or screen time. This can be managed as a break between book chapters, between Netflix episodes for tweens and teens, or timers set for younger children.

THE TWO HOUR RULE is based on guidelines from national and international expert organizations on child health, as described above.