Myopia (or short-sightedness) is known to be a complex problem, in which both “nature and nurture” play a part, says Dr Daphne Han, the eye expert we consulted. She calls it “in effect a disorder of eye-growth control”.
Nature: It is hereditary — if the parents have myopia, children are more likely to develop it, too.
Nurture: Tiring out your eyes (by holding your books too close for too long) constantly can likely make short-sightedness worse. Also, eating specific foods “for the eyes” isn’t necessary unless the doctor or nutrionist recommends it for your child’s growth — just a healthy, balanced, normal diet will do.
Studies have found that being outdoors is “protective against myopia” — Dr Han says the “duration, brightness and variability of outdoor light may be key” in how your short-sightedness develops. So let your children go outdoors as much as is practical, and have ample bright light indoors for doing “near work” (reading or playing with the computer or gadgets).
Dr Han’s Eyecare Tips
1. Limit unnecessary “near work” such as playing computer games or watching shows on handphones or tablets. Ensure that an at least 30cm is kept between the printed page or the phone/tablet screen, and the eyes.
2. Take frequent breaks to prevent eye fatigue (spasms of the eye muscles that control our focusing). Dr Han compares continuous reading/staring at the computer to carrying “a dumbbell for extended duration” — of course you end up with tired eyes, blurring of vision, eye pain and even headache. She suggests allowing the eyes to focus at a longer distance, or just simply closing them to let them rest for a few minutes every so often (every 15 minutes or so). There is, however, no conclusive study to prove that this helps in reducing myopia or in delaying the onset of myopia in children.
She adds: “Some eye exercises and accupoint massages have been in practice in various places such as China, America and Europe. Although these exercises had sometimes been shown to improve focus and reduce fatigue of the eyes, none of them had been conclusively proven to reduce or delay the onset of myopia.”
3. Don’t read while lying down as the reading distance is usually shorter; or while moving or in a vehicle as this can cause blurriness.
4. Make sure that the lighting is bright.
5. Having a balanced diet and healthy lifestyle with plenty of outdoor activities will also help.
6. Go for regular eye checks to ensure glasses are fitted properly and that there are no other eye problems.
Signs of myopia to watch for
In Singapore, pre-schoolers are screened for poor vision from a young age by the Health Promotion Board, and families are usually told. In general, if the child experiences blurring of eyesight or has difficulty seeing teaching material at school or on the TV, bring him or her for an eye test.
Other causes for concern are eye squinting, asymmetry of eye movement, watery, red eyes and eye-rubbing. It is important that the child has an eye check sooner rather than later, says Dr Han, as children whose visual problems are not corrected run the risk of developing lazy eye (amblyopia), a permanent, often irreversible state of poor vision.
Is rubbing the eyes dangerous?
“Eye rubbing has not been shown to cause or worsen myopia, but it can certainly contribute to astigmatism. Persistent and severe eye rubbing can even contribute to keratoconus, an eye disease, which if severe, may need to be remedied by a cornea transplant, usually in adulthood.”
Should you bring a myopic child for “specialised training”?
Dr Han says there is no scientific proof that eye exercises benefit myopia control. “However, rarer eye-movement and stereoscopic-vision (3D-vision) problems may co-exist alongside myopia. A case in point would be a myopic child who also suffers from convergence insufficiency, a condition that can be seen as a very subtle squint (misalignment of the eyes). These children should ideally have a complete eye examination before commencing on eye exercises specific for their conditions.”
I read some time back about special “spectacles”?
Some studies using bifocal, progressive or special “peripheral defocus” glasses have had “some effects in controlling myopia progression”, agrees Dr Han. But she states that the studies were not “very robust”. Strategies using soft contact lenses and orthokeratology (wearing of cornea-flattening rigid contact lenses during sleep) have also been tried. These require extremely careful management to prevent contact lens-related eye infections, “which although rare, can be devastating”, she warns.
Dr Daphne Han works with the Singapore Vision Center.