Myopia – What you should know
Myopia requires more attention than simply a pair of glasses. Children with myopia must be correctly diagnosed. Furthermore, attempts should be made to stop its progression, because a child’s long term eye health is at stake.
Controlling myopia in children is a huge modifying factor for lifelong risk of visual impairment
Here are 5 key points about myopia:
- If your long distance vision is blurry, but your near vision is clear, you may be myopic
- The prevalence of myopia is growing globally. In Australian 12 year olds, myopia doubled between 2005 and 2011 1
- By 2050, it is predicted that half of the world’s population – five billion people – will be myopic, with nearly one billion at risk of myopia related ocular pathology 2
- High myopia is strongly linked to higher risk of cataract, retinal detachment and myopic maculopathy 3. Consequently, myopia is linked to increasing rates of vision impairment and blindness. This is already evident in Asian countries 4, 5
- The World Health Organisation now recognises the public health issue of myopia, releasing a joint report with the Brien Holden Vision Institute in 2016 6
What is Myopia?
Myopia is also known as short-sightedness, or near-sightedness. It affects your ability to see objects in the distance clearly, while objects up close remain in focus. For example, reading road signs television, blackboards and recognising people in the distance can be difficult if you are myopic. Near objects such as books and phones are still clear and in focus.
Vision impairment and blindness later in life is linked to myopia. Even -1.00D of myopia carries an additional lifelong risk of posterior subcapsular cataract (PSCC), retinal detachment (RD) and myopic maculopathy (MM). Higher degrees of short-sightedness carry progressively higher risks.
Causes of Myopia
Eyeballs that grow too long become myopic. Eyes mostly grow during childhood but may also start to grow again in adulthood. When light enters an eye that is too long, the light is focused in front of the retina, rather than exactly on the retina. This causes blurry vision.
Child onset myopia is most commonly associated with eyes growing too quickly or continuing to grow into teenage years. Eyes should stop growing around 10-12 years of age. Myopia normally progresses more rapidly in younger children as their eyes are growing more rapidly.
Other know factors in developing short-sightedness are:
- spending more time on close work such as reading, computer games, drawing, smart phones and tablets
- the use of handheld electronic devices by toddlers at a younger age
- a person’s ethnicity and family heritage
- one short-sighted parent increases a child’s risk by 3 times, two short-sighted parents increases that risk by 6 times
- wearing the incorrect glasses or prescription, or wearing no correction when needed contributes to progressive short-sightedness
The primary symptom is blurry long distance vision (but clear near vision). Other symptoms include:
- squinting to see the blackboard
- moving closer to the TV screen
- tired eyes
- squinting or screwing up eyes
- under-performance at school
- difficulty reading road signs
It is important to recognised that children may not be aware of symptoms as they commonly think what they see is what everyone sees. Consequently, children and family members may miss symptoms or believe symptoms are not present. So, an Optometrist should examine children’s eyes at least every two years.
An Optometrist will conduct a number of tests in order to accurately diagnose myopia. You can also self assess your child’s risk factors by visiting My Kids Vision. This is not a substitute for an eye test, but can assist parents and teachers in identifying symptoms.
While myopia is easily measurable in the form of a glasses prescription, controlling myopia requires more than just a pair of glasses. Ultimately, it’s about controlling eyeball growth. A person that develops longer eyeballs is likely to suffer visual impairment for a longer duration of their life 7. So, the data provides a clear message to both patients and parents that controlling eyeball elongation (axial length) also controls lifelong risk of visual impairment.
So, simply prescribing glasses is not an adequate treatment. The evidence now shows that specialty contact lenses offer the best vision correction option to slow progression of myopia. Only an accredited Optometrist can prescribe and supply myopic controlling contact lenses.
Glasses that use specifically designed myopic control lenses can also help. Although not to the same extent as contact lenses, and only in cases with eye muscle teaming problems.
Atropine eye drops have also been shown to control myopic progression. However, these can be difficult to acquire as they must be made to order by qualified and specially equipped pharmacists.
Reduce your risk
- Early detection and correct treatment in young children is essential;
- Near vision tasks such as reading, homework or screen time (in addition to school time) should be limited in children;
- When using a computer or near screen, take a break every 20 minutes, for 20 seconds by looking away from the screen across the room;
- Position computer screens to avoid eye strain;
- Outdoor sport or play of at least 90 minutes per day can reduce myopia. Reading outdoors or using a phone outdoors doesn’t count;
- There is some evidence to suggest that outdoor light (sunlight) is beneficial in slowing onset and progression of myopia. However, good UV protection is still important, so wear a hat and UV protecting sunglasses.
The best way to reduce your and your family’s risk is to schedule regular eye health examinations. An Optometrist should examine children every 2 years from birth and throughout their school years. If you or family has not had an eye test in the last two years, book an eye test today.
Holden BA, Jong M, Davis S et al. Nearly 1 billion myopes at risk of myopia-related sight-threatening conditions by 2050 – time to act now. Clin Exp Optom. 2015;98:491-3.
Flitcroft DI. The complex interactions of retinal, optical and environmental factors in myopia aetiology. Prog Retin Eye Res. 2012;31:622-60.
Wu L, Sun X, Zhou X, Weng C. Causes and 3-year-incidence of blindness in Jing-An District, Shanghai, China 2001-2009. BMC Ophthalmol. 2011;11:10.
Iwase A, Araie M, Tomidokoro A et al. Prevalence and causes of low vision and blindness in a Japanese adult population: the Tajimi Study. Ophthalmology. 2006;113:1354-62.
World Health Organization. The impact of myopia and high myopia. 2016 Report.
Tideman JW, Snabel MC, Tedja MS et al. Association of Axial Length With Risk of Uncorrectable Visual Impairment for Europeans With Myopia. JAMA Ophthalmol. 2016;134:1355-63.