What is myopia and can you prevent it?

With short-sightedness on the rise, we investigate ways to manage and help prevent myopia in children and adults.

Myopia, also called short-sightedness, is a common condition in which close objects appear clear, but faraway objects appear blurry. It’s the most common eye problem affecting children and is rapidly growing around the world, reports the Brien Holden Vision Institute. In fact, around 30% of people globally currently have myopia and that figure is tipped to spike to 50% by 2050.

But why is it on the rise and what increases the risk of myopia developing? Some experts say spending too much time on screens, or indoors away from natural light, could be partly to blame.

Understanding the condition

Myopia usually begins in childhood (from age six onwards) and can worsen through to early adult years. It can also occur in adults with no prior history of eye problems and affect babies at birth (known as congenital myopia).

A myopic eye is too long from front to back, says the US National Eye Institute. As a result, light rays focus in front of the retina instead of on it, bringing clarity to close vision but blurriness far away. The retina is at the back of the eye.

Professor Padmaja Sankaridurg, head of the Global Myopia Centre at the Brien Holden Vision Institute, says that uncorrected short-sightedness in children can impact classroom involvement, social development and peer engagement. If uncorrected into adulthood, there can be further complications.

“High myopia increases the risk of vision impairment and also complications that may adversely affect sight, including myopic maculopathy, cataracts, glaucoma and retinal detachment,” she says.

Although the condition can’t be cured, corrective glasses or contact lenses to adjust the focus onto the retina can improve vision and reduce future deterioration. Prof Sankaridurg recommends regular testing and monitoring to ensure you stay on top of treatment.

Why is myopia on the rise?

Studies have shown that the risk of developing myopia can be hereditary.

“Short-sightedness tends to run in families, and a child with one short-sighted parent has three times the risk of developing myopia – or six times the risk if both parents are short-sighted,” says Whitney Lam, HCF senior optometrist at the Sydney City HCF Eyecare Centre.

It’s not just genetics at play, though. Staring at close objects such as books and screens for too long without regular breaks can also have an impact. Research suggests screen time increases the risk of myopia by 30% for constant mobile phone use and up to 80% for those who spend much of the day on a computer or laptop.

Unsurprisingly, groups more affected by myopia include children, people whose work involves using computers, adults who have a university education and children in academically selective schools.

While screen time can be part of a healthy lifestyle, you may find it useful to set usage limits within your household that are relevant to your family’s circumstances. And if you have to spend extended periods on screens, take regular breaks.

Other environmental factors that can contribute to the risk of developing myopia include a lack of time spent outdoors. “Higher density housing such as apartments with small windows, less natural light and limited distance views can also contribute,” says Whitney. Try to spend regular time outside with your children, partner or friends – outdoor hobbies like walking, archery, orienteering, cycling, hiking, and bird-watching can all help exercise your distance vision.

How light impacts the risk of myopia

There is growing evidence of the role of outdoor time (with safe exposure to natural daylight) on healthy eye development.

Researchers from the University of Sydney say exposure to sunlight at a young age assists in the growth of a healthy eyeball, preventing it from growing too fast or becoming too long (front to back), or oval-shaped instead of round. The Sydney Adolescent Vascular and Eye Study found that children who spent more time outdoors were less likely to have myopia, even if children were also doing a lot of reading and studying.

Prof Sankaridurg explains the benefits could be related to higher levels of light exposure outdoors compared to indoor environments, the composition of light, the fact that the pupil is smaller when outdoors, or the extended depth of field.

She recommends adults and children spend a minimum of two hours outside daily, with more time considered beneficial. Putting on a pair of sunglasses to stay sun safe won’t detract from the benefits, she adds, as daytime light levels are high.

While too much exposure to the sun’s UV light is harmful, safe exposure to natural light is key. For young children it could be gained, for example, through a morning play at the park, walking to and from school, after-school sports, and being outdoors at recess and lunchtime.

Clocking up healthy daylight time for adults could include enjoying lunch outdoors in the shade, walking to and from the train station or an early evening walk.

How to protect your child from myopia

A study involving Australian researchers found an extra 1.25 hours per day of outdoor time decreased the risk of myopia onset by 50%. Whitney agrees. “As an optometrist, I often say to parents, ‘more green time, less screen time’,” she says.

To further protect their children’s eyes, she also recommends parents:

• limit screen time after school to two hours or less
• encourage kids to spend 90 minutes a day outdoors while being sun smart, and being active for 60 minutes per day
• follow the 20/20 rule: when reading, writing or using a screen, children should take a break for 20 seconds after every 20 minutes of close focus on a screen or book
• use the elbow rule: the distance between your child’s eyes and any screen should roughly be the same length as your forearm.

Schools may also become part of the solution through measures such as building lighter, glass-constructed classrooms, teaching more lessons outside or making outdoor time a bigger part of the curriculum.

How is myopia treated in children?

Myopia treatment in children aims to slow down progression of the condition. According to Whitney, common approaches include:

• Orthokeratology: This involves reshaping the eye’s cornea by wearing specially designed firm contact lenses overnight while sleeping.
• Atropine eye drops, which studies show can help control myopia progression by relaxing parts of the eye involved in near focus.
• Contact lenses and/or multi-segment lenslet technology lenses.

Always discuss the best options for your child with your optometrist.

How is myopia treated in adults?

In adults, myopia usually develops more slowly due to excessive ‘near tasks’, such as smartphone use, extended time spent at a computer and watching TV. Treatment may include:

• distance glasses or contact lenses, which help to correct blurred vision
• digital lenses, which help reduce eyestrain when focusing on near-distance objects, such as digital devices
• laser eye surgery, which helps correct short-sightedness by reshaping the cornea.

When to get an eye test

Visit an optometrist for an eye exam if your child shows signs of sight problems such as:

• screwing up their eyes to see distant objects
• difficulty reading the whiteboard at school
• poor posture when reading, such as hunching over a book or pulling it close to their face
• lack of interest in playing outdoor games, as they may not be able to see well enough to confidently participate.

For adults, you might have difficulty seeing objects in the distance, such as road signs, scoreboards and faces.

Regular eye check-ups help diagnose problems early and correct your vision. Whitney advises children have yearly eye tests, while adults should have them every one to two years. As for when to take your child for their first eye examination, the Royal Australian and New Zealand College of Ophthalmologists says children’s eyes can be assessed at any age, as there are specialised techniques appropriate for age and development.

You may find it helpful to visit My Kids Vision, a free online tool that helps parents assess and manage myopia risks for their kids.

By Nicola Conville and Stephanie Osfield
Updated July 2022