What is myopia?
Myopia is blurry long-distance vision, often called “short-sighted’’ or “near-sighted”. A person with myopia can see clearly up close – when reading a book or looking at a phone – but words and objects look fuzzy on a blackboard, on television or when driving. But a pair of glasses aren’t the whole story.
Myopia in kids tends to progress or get worse throughout childhood, and higher levels of myopia are associated with higher eye disease risks in adulthood. If your child already wears glasses, you can do something to stop their vision worsening. If they don’t you can assess their risk of developing myopia.
- Myopia occurs when the eyeball grows too quickly in childhood, or starts growing again in adulthood
- Childhood onset myopia is most commonly caused by the eyes growing too quickly, or continuing to grow after age 10-12 when eye growth should normally cease. Genetics, environment and the individual’s characteristics can all contribute to this excess growth
- In younger children, myopia progresses more quickly because their eyes are growing at a faster rate, leading to higher levels of myopia, stronger glasses and more eye health risks
- Adult onset myopia usually occurs as an adaptation to fatigued eye focusing muscles due to a significant increase in close work, such as university studies
Why should I be concerned?
Myopia is becoming more common in children around the world.
The average age for developing myopia is reducing – younger onset means faster and more eye growth, which increases likelihood of high myopia and higher risk of eye diseases such as the following:
- Retinal detachment – the light sensitive ‘film’ lining the back of the eye pulls away from its base, causing distorted vision or blindness depending on its location
- Myopic macular degeneration – loss of central vision clarity, like having a thick smudge permanently in the middle of your vision
- Glaucoma – increased pressure in the eye which damages peripheral vision, called the ‘sneak thief of sight’ as very few people who have it notice its symptoms until it is very advanced
- Cataract – a cloudy window in the middle of the eye, like looking through a foggy windscreen
What causes myopia?
- Spending more time on close work has been linked to development of myopia, such as reading, playing computer games, drawing or using smart phones and tablets
- Electronic hand held devices are easy for toddlers to use resulting in increased exposure to close work at a younger age
- Myopia can be hereditary, and a person’s ethnicity and family background can increase the risk
- Research suggests a link between Asian ethnicity and faster progression of myopia, with higher worldwide prevalence in this group of people
- A person with one short-sighted parent has three times the risk of developing myopia – or six times the risk if both parents are short-sighted
- Under or over-corrected vision (incorrect glasses, or having no glasses when they are needed) has been shown to promote onset and accelerate progression of myopia
How can I prevent or slow myopia?
- Catching early signs of myopia before it fully develops can help slow onset and progression
- Children should not spend more than three hours a day – in addition to school time – on close work such as reading, homework or screen-time
- When using a computer, ensure it is properly positioned to avoid eye strain and take breaks every 20 minutes by looking across the room for 20 seconds
- Smart phones are popular for children and teenagers’ texting, social media, reading and games – but too much screen time is linked to myopia, can cause dry eyes, and increase risk of eye damage and diseases in adulthood similar to UV damage
- The blue-white bright light from tablets and phones can damage long-term eye health and affect sleep – while there are no guidelines yet on how much to limit a child’s overall time spent on screens, these devices should be avoided by children and adults for three hours before bedtime
- Outdoor sport and play of at least 90 minutes a day can reduce the risk of myopia – looking at your tablet or phone when outside doesn’t count!
- There is evidence to suggest that exposure to outdoor light is beneficial in slowing onset and progression of myopia – but UV protection is still important so wear sunglasses and a hat