Short-sightedness — or myopia — is something I’m seeing more and more of in children, and I’m not alone. Across the UK, the number of school-aged children developing myopia has risen dramatically over the past two decades. It’s estimated that around one in five children in the UK are now myopic, and current projections suggest that by 2050, half the global population could be short-sighted.
That’s an astonishing shift in how our children are seeing the world — and the effects can be much more serious than just needing glasses.
What is short sightedness and how much does it matter?
In simple terms, short-sightedness means that distant objects — like the classroom whiteboard or road signs — look blurry, while things up close are usually clear. It happens because the eye grows too long from front to back, so light entering the eye focuses in front of the retina instead of directly on it. The result is that the world beyond arm’s length becomes blurry. Glasses or contact lenses can correct the focus, but they don’t stop the eye from growing, which is what we’re really concerned about.
Although myopia may start as an inconvenience, high levels of it can increase the risk of more serious eye problems later in life. The longer the eye becomes, the more stretched and fragile the internal structures can become. For each step up in myopia — even just one unit of prescription (known as a dioptre) — the risks increase. For example, the lifetime risk of retinal detachment, where the retina peels away from the back of the eye, goes up by about 30% with every extra dioptre. Someone with a -6.00 — high myopia — prescription or greater has more than ten times the risk of retinal detachment compared to someone without myopia.
The chances of developing glaucoma — a condition that damages the optic nerve and can cause vision loss — also rise steadily with worsening myopia. In high myopia, the risk of certain types of cataracts and a condition called myopic macular degeneration, which affects central vision, increases significantly. So the earlier and more severely myopia develops, the more important it is to manage — not just to keep the prescription low, but to protect long-term eye health.
So, why are we seeing such a surge in cases?
What’s changed is how our children are growing up — how they study, play, and spend their time.
The main risk factor is prolonged near work. That includes reading, writing, homework, and — more recently — tablets, smartphones and computers. These tasks place sustained focusing demands on the eyes, and without regular breaks or outdoor time, the eye is more likely to grow too long. Posture matters too. Children lying on their stomachs while reading or using screens tend to hold the book or device far too close — often less than 15 cm from their eyes. This very short viewing distance places even more strain on their focusing system.
Genetics do also play a role. If one parent is short-sighted, the risk to their child is roughly doubled. If both parents are, the risk is more than five times higher. But genetics can’t explain the steep global rise in such a short time.
How do we prevent it?
The biggest protective factor we know of is time spent outdoors. Children who spend at least two hours a day outside in natural daylight are significantly less likely to develop myopia. It doesn’t need to be sport — just being outdoors, walking, playing, or sitting in the park seems to help regulate healthy eye growth. The effect is strongest when this habit starts early, ideally before age 7.
Encouraging children to sit upright with books and screens at least elbow- distance away can make a big difference. Good lighting is also important. A well-lit room and a proper reading light over the shoulder help reduce eye strain during homework or reading.
Handheld devices are part of everyday life now, and I’m not suggesting banning them altogether — but it’s worth setting healthy habits early, especially to hold screens at a good distance (arm’s length or greater).
- Children under two should ideally avoid handhelds altogether.
- From ages 2 to 5, I suggest to keep to less than 30 minutes per day.
- Between 6 and 12 years, one hour of recreational screen time per day is a reasonable upper limit — schoolwork will come on top of that, so regular breaks become especially important.
- For teenagers, screen use will naturally increase, but we still encourage the “20-20-20” rule: every 20 minutes of close-up work, take a 20-second break to look at something 20 metres away, and aim for 2 hours outdoors daily.
If your child is already short-sighted, the good news is that we now have several ways to slow its progression. Glasses remain the simplest and most common starting point, but there are now special types of lenses — myopia control glasses or contact lenses — that can help slow the rate of eye growth. In some cases, we also use low-dose atropine eye drops, which have been shown to significantly reduce the speed at which myopia worsens in children. Each approach is tailored to the child’s age, lifestyle, and prescription — we don’t treat everyone the same way, and not every option is right for every child.
A simple eye exam is the first step
Most importantly, regular eye checks help us detect issues early — before a child is struggling in class or falling behind in sport. Many children assume that blurry vision is just how everyone sees, and won’t necessarily mention it. If there’s a family history of myopia, or if your child is showing signs like sitting very close to the TV, squinting at the board, or losing interest in reading, it’s worth getting them checked sooner rather than later. Occasionally one eye can be more short-sighted and even ‘lazy’ without any outward sign.
So what actually happens during a children’s eye exam?
It’s a short, simple process that usually only take an hour at most.
You will usually see two specialists, an orthoptist who will assess a child’s visual behaviour and then an ophthalmologist who will examine the structure of the eyes and may do a glasses test.
For toddlers, those with extra needs and younger children, we make the experience as friendly and engaging as possible. We use picture charts instead of letters, watch how the eyes move and work together, and check the focus using a light and a handheld lens — there’s no need for a child to read or explain anything. We will need to instil eye drops to enlarge the pupils to allow us to complete this examination. Be prepared for the entire consultation to take approximately one hour.
For older, or more cooperative, children and teenagers, we may do more specialised tests on top of this, for example scans that determine the length of the eye, but always in a relaxed, jargon-free way. We aim to explain things clearly, involve the child where ppropriate, and reassure both them and you throughout.
At St John and St Elizabeth Hospital in St John’s Wood I work alongside my orthoptist colleagues, Mr Altaf Natha and Ms Louise Brocklesby, in a clinic dedicated to children’s eye health. Whether it’s a routine check-up, a concern about myopia, or something more complex, we’re here to help with expertise, kindness, and no unnecessary fuss.
If you’d like to ask a question for a future issue, or if you’re wondering whether your child might benefit from an eye check, please feel free to get in touch.
Let’s keep children seeing clearly — now, and for the future.
Marcus Posner
Marcus Posner MBBS, BSc (Neuroscience), FRCOphth
Consultant Ophthalmologist
Chelsea Surgical Partners @ St John & St Elizabeth
Hospital, St John’s Wood
Email: Linda@ChelseaSurgical.org
Website: www.chelseasurgical.org
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