Myopia, commonly called short-sightedness, is a condition where the eye can see nearby objects clearly but struggles to focus on things in the distance. It is one of the most common vision conditions in Singapore and it tends to develop in childhood, often between the ages of six and fourteen. In Singapore, approximately 65 per cent of children are myopic by the age of 12. Understanding why myopia develops and why it tends to worsen during childhood is the first step in making informed decisions about your child's eye care.
What exactly happens to the eye when myopia develops?
Myopia develops when the eyeball grows slightly too long from front to back. This is called axial elongation. When the eye is longer than it should be, light that enters through the lens focuses in front of the retina rather than directly on it. The result is a blurred image for anything at a distance.
This is not a problem with the lens of the eye. The lens can adjust its shape to some degree, but it cannot compensate for an eyeball that has grown too long. Spectacles and contact lenses work by adjusting where incoming light focuses, correcting the blur without changing the physical structure of the eye.
Myopia is measured in dioptres, written as a negative number on a spectacle prescription. A reading of negative 1.00 is mild. Negative 3.00 to 6.00 is moderate. Above negative 6.00 is classified as high myopia.
Why does myopia tend to get worse as children grow?
Children's eyes grow as they grow. Between the ages of six and sixteen, many children experience periods of rapid axial elongation, which causes myopia to worsen year after year. At each annual review, the optometrist may find that a child's prescription has increased, sometimes by a significant amount.
This progression is not uniform across all children. Some experience slow, steady increases. Others have periods of rapid change, often coinciding with growth spurts. Once axial elongation occurs, it does not reverse. This is why early management, aimed at slowing the rate of change, is considered clinically worthwhile.
The concern with high myopia is not simply that it requires stronger glasses. Eyes with high myopia have a longer axial length, which stretches the retinal tissue and increases the risk of serious conditions in adulthood, including retinal detachment, glaucoma, and myopic macular degeneration. Managing progression during childhood reduces the likelihood of reaching high levels of myopia.
What factors influence how quickly myopia progresses?
Several factors are associated with a higher likelihood of myopia developing or progressing more rapidly.
- Both parents have myopia. If both parents are myopic, a child has a significantly higher risk of developing it and of experiencing faster progression. If only one parent is myopic, the risk is elevated but lower.
- Limited outdoor time. Research consistently shows that children who spend more time outdoors have a lower rate of myopia progression. Natural light is believed to stimulate retinal dopamine release, which plays a role in regulating eye growth. Current clinical guidance recommends at least 90 minutes of outdoor time daily for children.
- High near work demand. Extended reading, writing, and screen use without adequate breaks is associated with myopia progression in multiple studies, though the mechanism is not fully understood.
- Early onset. Children who develop myopia before the age of eight tend to have a longer period ahead of them during which progression can occur. Early onset is associated with a higher likelihood of reaching moderate to high myopia by adulthood.
How do optometrists assess myopia in children?
A myopia assessment goes beyond a standard vision check. In addition to measuring the current prescription, an optometrist conducting a myopia assessment will typically measure axial length, which is the physical length of the eyeball from front to back. This measurement is the most direct indicator of myopia and its progression over time.
Comparing axial length across reviews allows the optometrist to track how quickly the eye is growing and to adjust the management plan accordingly. A prescription alone does not capture the full picture.
For children who have not previously had a myopia assessment, the first visit will establish a baseline. Subsequent reviews, typically every six to twelve months, track change over time.
At what point should parents consider myopia management?
A prescription change of 0.50 dioptres or more per year is generally considered significant and warrants a discussion about management options. Some children progress more quickly than this, and a conversation about management is appropriate at any stage where progression is evident.
If your child's prescription has increased at two consecutive annual reviews, it is worth asking your optometrist specifically about myopia management. Waiting until the prescription reaches a particular level before acting means missing the window during which management is most effective.
What options are available to slow myopia progression?
Several clinically studied approaches are used in myopia management. Each works differently and suits different children depending on their age, prescription, and lifestyle.
- Orthokeratology (ortho-k): rigid contact lenses worn overnight that reshape the cornea temporarily, allowing clear vision during the day without spectacles or daytime lenses. Ortho-k has a strong evidence base for slowing axial elongation in children.
- Myopia control spectacle lenses: specially designed spectacle lenses with peripheral defocus optics, intended to reduce the visual signal that drives axial elongation. Examples include MiYOSMART and Stellest lenses.
- Low-dose atropine eye drops: a pharmacological approach that has been studied extensively in Singapore and Asia. Low concentrations, typically 0.01 per cent or 0.05 per cent, have shown a meaningful effect on slowing progression with minimal side effects in most patients.
No management option reverses myopia that has already developed. The goal is to slow the rate at which the prescription increases, reducing the long-term risk associated with high myopia. An assessment by a qualified optometrist is the first step in determining which approach is appropriate for your child.
Frequently Asked Questions
Can myopia be cured?
Myopia cannot currently be cured. Spectacles and contact lenses correct the blurred vision but do not alter the underlying eye length. Management options aim to slow progression during childhood, not reverse changes that have already occurred.
Is it safe to leave myopia without treatment?
Mild, stable myopia that is corrected with spectacles does not typically require active management. Progressive myopia that is increasing significantly year on year benefits from management to reduce the risk of high myopia developing in adulthood.
My child is only six. Can they already have myopia?
Yes. Myopia can develop from school-going age. Some children are identified at their first school eye screening. An assessment at any age where vision concerns arise is appropriate.
Does screen time cause myopia?
Screen time alone has not been proven to cause myopia. Sustained near work, of which screens are one form, is associated with myopia progression in some studies. Reduced outdoor time is considered a stronger contributing factor in current evidence.
How is a myopia assessment different from a standard eye test?
A myopia assessment includes axial length measurement, which tracks the physical growth of the eye. A standard eye test measures the prescription but does not capture this information. If your child has been diagnosed with myopia, a dedicated myopia assessment provides a more complete clinical picture.
