How much time outside protects kids' eyesight?

The short answer

Yes, time outdoors helps protect kids from becoming short-sighted. Eye researchers broadly agree that 10 to 15 hours a week outside is enough to help prevent it. That works out to about 2 hours a day (University of Technology Sydney). The good news for Aussie summers is that shade and hats still let in plenty of protective light (Review of Optometry).

Key takeaways

• About 30% of the world's population is short-sighted. The World Health Organization expects that to reach 50% by 2050 (UTS).
• 27% of Australian children who had an eye test with Bupa Optical in 2025 were diagnosed as short-sighted (Insight News, 2026).
• In a trial with almost 2,000 Chinese first graders, an extra 40 minutes outdoors each school day cut new cases. After three years, about 30% of those kids were short-sighted, compared with almost 40% in schools without the change (Scientific American).
• Light under a tree or a hat is still 11 to 43 times brighter than indoors, so sun-safe outdoor time still counts (Review of Optometry).

What is short-sightedness, and why does it matter?

Short-sightedness (doctors call it myopia) happens when the eyeball grows too long. Light then focuses in front of the retina, the light-sensing layer at the back of the eye, instead of on it. Close things look sharp, but distant things look blurry (UTS).

Glasses fix the blur, but the longer eye carries risks later in life. Moderate myopia is linked to a higher risk of early glaucoma and cataracts. High myopia carries a much higher risk of vision loss and blindness (UTS). That's why slowing it down in childhood, while eyes are still growing, matters so much.

Why does being outside help?

The leading theory is bright light. Professor Kathryn Rose, Head of Orthoptics at UTS, explains that time outdoors releases dopamine in the retina. Dopamine is a chemical messenger that helps control how fast the eye grows (UTS).

Screens were the first suspect, but many researchers now point to the time kids are no longer spending outside instead (UTS). Trials in Taiwan and China have found that adding outdoor time reduces new cases.

The best-known trial ran across 12 schools in Guangzhou, China. It was led by Dr Mingguang He of Sun Yat-sen University and published in the journal JAMA in 2015. Kids in the outdoor group were 23% less likely to become short-sighted (Scientific American).

How much outdoor time is enough?

Aim for around 2 hours a day. Eye researchers broadly agree that 10 to 15 hours a week outdoors is enough to help prevent myopia (UTS).

Queensland University of Technology tracked children's daily light with wrist-worn sensors. Kids with the least outdoor light had faster eye growth and faster myopia progression. QUT's Associate Professor Scott Read recommends at least 2 hours outside each day. He also flags less than 60 minutes as a risk factor (Education Matters).

It doesn't have to happen all at once. Time outdoors adds up across the day: the walk to school, recess, afternoon play.

Does it still work in the shade with a hat on?

Yes. A 2019 study by Lanca and colleagues measured light levels in Singapore. The level thought to protect against myopia is about 1,000 lux. Lux is a unit of brightness. Every sun-safe option stayed well above it (Review of Optometry).

Source: Lanca et al. (2019), reported by Review of Optometry.

How do we keep outdoor time sun safe?

Follow the five SunSmart steps whenever the UV Index is 3 or higher (Royal Children's Hospital Melbourne):

• Slip on clothing that covers as much skin as possible.
• Slop on SPF50 or higher broad-spectrum, water-resistant sunscreen, and reapply every 2 hours.
• Slap on a broad-brimmed, legionnaire or bucket hat.
• Seek shade, remembering UV still reaches kids there.
• Slide on sunglasses labelled category 2, 3 or 4.

UV is usually strongest between 10am and 4pm. Keep babies under 12 months out of direct sun when the UV Index is 3 or higher (RCH). Early mornings and late afternoons are ideal for outdoor play: bright light, lower UV.

Where jumpIN fits

On the Northern Beaches, 2 hours outside is easier than it sounds: a morning rockpool walk, an after-school play at the park, or an outdoor class on the weekend. We're parents here too, and that's why jumpIN has a free activities section for playgrounds, community events, markets and fairs. Outdoor classes like junior surf, tennis or nature play can be booked one session at a time, with every provider's safety checks and qualifications shown upfront. Find something outside this week at jumpinclasses.com.

FAQ

How many hours outside does my child need to protect their eyes? About 10 to 15 hours a week, or around 2 hours a day (UTS).

Is it screens that cause short-sightedness? Many researchers now point to less time outdoors as the bigger factor (UTS).

Does sitting in the shade still count? Yes. Tree shade measured 5,556 to 7,876 lux, far above the roughly 1,000 lux thought to protect against myopia (Review of Optometry).

Sources

• University of Technology Sydney, Rise in short-sightedness linked to less time outdoors (February 2018, adapted from ABC, March 2017).
• Scientific American, More Time Outside Tied to Less Nearsightedness in Children (September 2015, reporting He et al., JAMA 2015).
• Education Matters, Two hours of outdoor light reduces myopia in children (undated; QUT research).
• Review of Optometry, Strategies Protect Against Sun, Myopia (August 2019, reporting Lanca et al., Translational Vision Science and Technology 2019).
• Insight News, Optometrists stress more outdoor time as child myopia surges (January 2026, Bupa Optical data).
• Royal Children's Hospital Melbourne, Sun safety fact sheet.

Written by the jumpIN team, parents on the Northern Beaches.