Myopia, also known as short sightedness is one of four types of refractive errors where the cornea elongates and changes the way light comes into the eye. This causes light rays to focus in front of the retina instead of onto the retina, and distant objects turn to a blur whilst near objects remain clear. In this article, we focus on how to prevent myopia from worsening.
Myopia often occurs with astigmatism, another type of refractive error which affects where the eye focuses light on. Astigmatic eyes are often described to be in the shape of a rugby ball.
Instead of a uniform single focus point, astigmatism refracts light to multiple focus points after passing through the eye and people with astigmatism have trouble seeing objects both up close and far away.
Together, these refractive errors determine the power of the corrective lenses prescribed.
The World Health Organisation (WHO) estimates that half of the world’s population will be myopic by 2050. According to published studies, the prevalence of myopia is highest in east Asia, where China, Japan and the Republic of Korea have a prevalence of approximately 50%. In Singapore, 80% of young adults are myopic.
How to prevent myopia from worsening
It is particularly worrying when a child is diagnosed with myopia at a young age as the condition tends to progress faster since their eyes are growing at a faster rate.
To put it in perspective, children between the ages of five and 15 are at a higher risk of myopia progression.
For every year that myopia is left unmanaged, the degree can increase by as much as 150. Beyond just the inconvenience caused by blurry vision, high childhood myopia also increases the likelihood of eye diseases such as retinal detachment, cataract and glaucoma in adulthood.
Managing myopia risk
How much time your child spends outdoors may be one of the most important underlying risk factors to how early myopia sets in, and how far myopia progresses.
An increasing body of evidence has shown that those with the highest exposure to sunlight, especially as teenagers and young adults, had about a 30 per cent lower risk for myopia than those with lower exposure.
During outdoor play and sports, the eyes are exposed to distant objects with a wide field of focus and sunlight also stimulates the production of vitamin D which strengthens our eye sclera structure.
Correspondingly, myopia risk is consistently associated with intense near work activities including studying, reading, watching television and screen time.
At seven years of age, 20 per cent of Singapore children are myopic and the severity increases dramatically after six years of age when children enter school full-time. To reduce the impact of prolonged near work activities, time spent outdoors may very well be the intervention our indoor generation needs today.
Fostering healthy eye habits such as taking regular breaks from near work activities and optimising lighting to reduce eye strain are also recommended to maintain optimal eye health and minimize myopia risk.
When myopia strikes
An eye examination to check for refractive error is the first step to determine if your child has myopia and/or astigmatism. Once diagnosed, corrective glasses are prescribed in most cases to provide temporary relief.
But with contact lens material and design becoming safer and more comfortable than ever, it is becoming a popular corrective option as it has the advantage of giving clearer and wider peripheral vision.
These are important considerations for parents with active children engaged in sports as optimal vision is mandatory for good performance. Furthermore, contact lenses are also more compatible with the safe use of sporting equipment.
As contact lenses are medical devices, it should be prescribed only after a thorough eye examination, consultation to understand lifestyle and vision correction needs, followed by contact lens fitting.
These can be done in one session with a qualified optometrist who will review the eye health, check for refractive errors and determine the size and shape of both eyes so that the lenses fit properly. During the consultation, the child should also be provided with trial lenses, so they can learn how to insert and remove the lenses. At this point, the optometrist will be able to assess if the eyes are wide enough for easy insertion and removal.
Whilst contact lenses are commonly used by children as young as seven years old, it is important to consider if the child is responsible enough to wear the lenses correctly and understands the importance of maintaining contact lens hygiene.
As the eyeballs continue to grow during the formative years and only stabilise in adulthood, regular eye examination every six to 12 months is recommended to catch myopia early and to monitor the progress at the onset of myopia.
Every pair of eyes are different, and parents should speak to the optometrist to determine the most ideal intervention and myopia management strategy to slow the progression when the number is on the lower end of the spectrum.
*This article was contributed by Mr Chew Wai Kwong, Optometrist, Videre Eyecare (In partnership with Johnson & Johnson Vision Care)
Also READ: Tips to prevent myopia in children