Tips for safe screen time

How much screen time is too much for both children and adults?

Based on evidence, the recommended time limitation on screen usage for children two to five years of age is not more than one hour per day. Although older children and adults are allowed more screen time, it is still recommended to limit it up to two hours a day. Time spent on screen usage should not take the place of adequate sleep, physical activity, and other behaviours essential to health. For children younger than 18 to 24 months, it is best to avoid digital media use (except video-chatting), but if you need to introduce digital media, choose high-quality programmes and be sure to view them together with your child in order to control the screen time.

What are the common risks associated with too much screen time?

Eyes need to stay moist to stay healthy, but screen time can result in dryness and eye irritation. When you blink, your eyes release a “tear film” that soothes and coats your eyes. However, during screen time, the eyes are focused on an object for an extended period of time, thus the blink rate decreases in both children and adults, resulting in increased evaporation, drier eyes, fatigue, and eye strain.

In addition, excess screen time at a near distance means fewer opportunities for the eyes to adapt to outdoor sights. This will result in higher risk of myopia (short sightedness) in children. Also, gazing at the same near distance for an extended time can cause the eye's focusing system to spasm or temporarily “lock up”. This condition, called an accommodation spasm, causes a child's vision to blur when he or she looks away from the screen. In serious cases, eye drops to relax the accommodative muscles may be needed.

Can you recommend strategies to minimise the detrimental effects of screen time?

Firstly, monitor screen time and content. Take frequent breaks and remind children to do so to avoid symptoms of eyestrain. There is the 20/20/20 rule that can be applied: look away from the screen every 20 minutes to focus on an object at least 20 feet away for at least 20 seconds. In addition, children should turn away from the screen for at least 10 minutes every hour.

Another important factor is to remember to blink. Eye drops or a room humidifier may be used to maintain eye moisture.

Screen positioning is also important. Make sure the screen on the desktop or laptop computer is slightly below eye level. Looking up at a screen opens eyes wider and dries them out quicker. Adjusting the font size, especially on smaller screens, may also help reduce eye fatigue. Finally, remember to get regular vision screenings for both adults and children.

Dr Leo Seo Wei is senior consultant ophthalmologist at Dr Leo Adult & Paediatric Eye Specialist Pte Ltd in Singapore.

This story was originally published in the Global Health and Travel issue of August-September 2018.