Are Tablets Bad for Children's Eyes? Distance and Time Guidelines

Japan’s education ministry (MEXT) published its school health statistics for the 2025 school year on February 13, 2026. The share of students whose uncorrected visual acuity was below 1.0 was over 30% in elementary school, around 60% in junior high and around 70% in high school, rising with each stage. Acuity below 1.0 has causes other than myopia too, so this is not the same as the share of children with myopia.

In Japan, elementary school children each use a device at school, and many also look at a tablet at home. Some parents wonder what this does to their children’s eyes.

In this article I gather the guidelines that public bodies and medical societies have published, with their sources, and then think about how to use a tablet at home with them in mind.

What the sources say, in short

Taken together, they come down to this:

There is no evidence that the light from screens itself damages the eyes.
Looking at things up close for long periods, and spending little time outdoors, are thought to be linked to myopia.
So the advice is to keep some distance, look far away from time to time, and make time to be outside.

In other words, the answer to “Are tablets bad for children’s eyes?” is that it depends on how they are used. Let’s look at the sources one by one.

Distance and break guidelines

MEXT’s leaflet

MEXT publishes a leaflet on children’s health when using devices, in versions for elementary students, older students and parents. The parents’ version lists three health points:

Keep the eyes at least 30 cm (about 12 inches) from the screen. Good posture is important for this, and the desk and chair height should be adjusted as the child grows.
Once every 30 minutes, look away from the screen at something far away for at least 20 seconds.
Adjust the screen brightness to the brightness of the room.

The leaflet adds that points 1 and 2 matter when reading paper books and documents too. It is not only about tablets.

As a minimum, it also asks families to stop using digital devices at least one hour before bed. The reason given is that strong light before sleep interferes with melatonin, a hormone that helps us fall asleep. On total time, it says that because it depends on how devices are used, it cannot give a single number of hours that is fine.

MEXT’s guidebook

Earlier, in 2014, MEXT published a guidebook on using ICT with attention to students’ health (in Japanese). It is mostly about schools, but includes some guidance for families.

On posture, it says there is no “one correct posture”, and what matters is not working in a strained posture for a long time. On looking at tablets for long periods, it notes that a guideline for adult office work in Japan suggests keeping continuous intensive work under one hour, and says that the amount of use in school lessons is not thought to affect health. It also states that the expert comments reflect information as of the 2013 school year and may be revised.

Japan Ophthalmologists Association

The Japan Ophthalmologists Association’s awareness comic for children (2021, in Japanese) asks children to:

Sit up straight and keep the eyes at least 30 cm from the screen.
Once every 30 minutes, look far away for at least 20 seconds to rest the eyes.
Blink often so the eyes don’t dry out.
Rest the eyes at break time and move around outside in the daylight.
Stop looking at screens one hour before bed.

The distance and break numbers match MEXT’s leaflet. If a family wants one thing to remember, it is “30 cm, 20 seconds every 30 minutes, and one hour before bed.”

About the 20-20-20 rule

In English-speaking countries the “20-20-20 rule” is often mentioned: every 20 minutes, look at something 20 feet away for 20 seconds.

A study published in 2023 tested the rule (Talens-Estarelles and colleagues, Contact Lens and Anterior Eye, 2023). Twenty-nine computer users with eye symptoms received break reminders based on the rule for two weeks. Their eye strain and dry eye symptoms decreased. But one week after the reminders stopped, the improvement was gone, and most measurements of the eye surface and binocular vision did not change. The participants were adults, and the study was small.

So the 20-20-20 rule has some support as a break habit to ease eye strain, but it has not been shown to prevent myopia in children. The American Academy of Ophthalmology’s page for parents, “Screen Use for Kids”, doesn’t use the 20-20-20 numbers either. It says to look up from the device at something in the distance for a bit. Japan’s “20 seconds every 30 minutes” can be read as the same idea.

Time outdoors and myopia

On myopia, the advice the sources agree on is time outside.

In a study in Guangzhou, China, first graders at 12 elementary schools took part, and six of the schools added one 40-minute outdoor class to every school day, with parents encouraged to take children outside after school (He and colleagues, JAMA, 2015). Over three years, 30.4% of children in the outdoor group developed myopia, compared with 39.5% in the other group.

In a study in Taiwan, first graders were encouraged to spend break time outdoors for a year, and children at those schools showed less shift toward myopia (Wu and colleagues, Ophthalmology, 2018). The study looked not only at time but also at time spent in light of 1,000 lux or more.

A presentation by a board member of the Japan Ophthalmologists Association at a 2023 press briefing likewise summarizes that around two hours a day of outdoor activity shows an effect in suppressing myopia. The AAO page also says that spending time outdoors, especially in early childhood, can slow the progression of nearsightedness.

There is also the idea of adding time outside, not only cutting tablet time.

Time guidelines: WHO and the AAP

Guidelines on how long children use screens are less about the eyes and more about a child’s whole day.

In 2019 the WHO published guidelines on physical activity, sedentary behaviour and sleep for children under 5. Sedentary screen time is not recommended for 1-year-olds, and for ages 2 to 4 it should be no more than one hour a day, with less being better. The same guidelines recommend that children aged 1 to 4 spend at least 180 minutes a day in a variety of physical activities.

The American Academy of Pediatrics revised its policy in 2026, shifting from fixed time limits toward attention to content, context and conversation between parent and child (Helping Kids Thrive in a Digital World: AAP Policy Explained). I wrote about ages in What Age Should Kids Get an iPad?.

About blue light

Blue light is another common worry. On April 14, 2021, six Japanese bodies, including the Japanese Ophthalmological Society, the Japan Ophthalmologists Association and the Japan Myopia Society, issued a joint statement urging caution about blue light glasses for children (in Japanese).

The statement says the blue light from device screens is less than natural light on a cloudy day or through a window, and has been reported to be at a level that does not harm the retina. It goes on to say that sunlight is good for children’s development and that not getting enough of it raises the risk of myopia progressing, and concludes there is no basis for recommending blue light glasses for children. At the same time, it notes that strong light late at night may affect sleep, so reducing blue light in the evening may have some effect.

The AAO page also says there is no scientific evidence that light from computer screens damages the eyes, and that the Academy does not recommend blue light glasses for computer use.

Screen Distance on iPad

iPad and iPhone have a feature called Screen Distance. According to Apple’s support page “What is Screen Distance?” (published September 14, 2026), it uses the TrueDepth camera to detect when you hold your iPhone or iPad closer than 12 inches for an extended period, and encourages you to move it farther away.

To turn it on or off:

Open the Settings app, scroll down, then tap Screen Time.
Tap Content & Privacy Restrictions.
Tap Screen Distance, then turn it on or off. You might be asked for a Screen Time passcode.

When the screen is too close, an alert covers it and you can’t continue. Moving the iPad more than 12 inches from your face, or tapping Continue, removes it.

There are three things worth knowing.

It’s on by default under 13. It is turned on by default for children under 13 in a Family Sharing group, though the age varies by region. Each time your child updates a device signed in with their Apple Account, it is turned back on for all their devices.

Only some iPads have it. It works only on devices with a TrueDepth camera, the same camera used for Face ID, running iOS 17 or iPadOS 17 or later. Apple’s list of “iPhone and iPad models that support Face ID” includes only iPad Pro models among iPads. The iPad, iPad mini and iPad Air that are often chosen for children don’t have it.

The distance is the same 30 cm. Twelve inches is the same distance MEXT and the Japan Ophthalmologists Association use. On an iPad without the feature, an adult’s reminder is all there is.

How to manage your child’s settings from your own device is in How to Set Up Screen Time on an iPad for Your Child.

When your child learns with Kinder Browser

Kinder Browser, which I make, keeps the screen from turning off while a page is shown, so the screen doesn’t go dark in the middle of learning. When I was asked about this in the developer interview, I said:

Because it’s more convenient that way.

But a screen that stays on also means the device won’t prompt a break. Breaks and the end time are set by adults and by the iPad’s own tools, not by the browser.

The end time. Use Time Allowances and Screen Time Schedule in Screen Time to set daily time and the hours it can be used. When lending your own iPad, a Guided Access time limit can set the end. The steps are in Lending Your iPad to Your Kids and How to Use Guided Access on iPad.
A break every 30 minutes. A kitchen timer works. Decide in advance that when it rings, your child looks out the window or gets up for a drink of water.
The hour before bed. Use the schedule so the iPad can’t be used in the evening.

The parental page also has a Blue Light Cut switch. It is there to protect children’s eyes. Turning it on puts an orange filter over the whole screen and cuts the blue light coming from it. You can turn it on when your child uses the app in the evening, and close the screen an hour before bed as well.

Then there is desk and chair height. With an iPad lying flat on a desk, children lean over it and the distance shrinks. Standing the screen up a little on a stand should make 30 cm easier to keep. If your child keeps squinting or bringing their face close to the screen, you can see an eye doctor rather than wait for the school checkup.

About Kinder Browser

Kinder Browser is a web browser for children on iPhone, iPad and Mac. Your child can open only the home page and bookmarked sites you have added. Links within those sites work, but links to other sites stop with “External links are disabled”. Adult and gambling sites are blocked by a built-in list. The settings sit behind a parental gate, and the app collects no data.

It is a one-time purchase, $9.99 in the US and ¥1,500 in Japan, with no in-app purchases, no subscription and no ads. The first setup is covered in Getting Started with Kinder Browser, and preparing a new iPad for a child in Giving a Child an iPad for Christmas.