Myopia is the technical term for near-sightedness. Those who are myopic have trouble making out distant objects, but close objects remain clear.
What are the study's key findings?
East Asia's big cities - which stress the importance of academic success - have very high rates of myopia. Far more than their western counterparts.
Does race play any role in myopia?
Yes. Genetically, the Chinese have a greater tendency to become myopic.
But Singapore's experience where the three major ethnic groups - Chinese, Malay and Indian - have seen sharp jumps in myopia rates also suggest that there could be more than genetics involved.
Prof Morgan says the change has been too quick and "gene pools just don't change in two generations".
How can parents tell if their child has myopia?
Dr Ang says parents should take note if their child suddenly hold objects close to his face as it may be an indication of blurred vision.
Sometimes, a child may squint while looking at distant objects. On other occasions, he may tilt his head at an odd angle.
Dr Ang advises parents to take their child for an eye check-up if they sense anything amiss.
However, it is not easy to pick up mild myopia. Children are unlikely to speak up about it as they may not know that having blurred vision is abnormal.
When should parents worry?
If the child's degree of myopia increases significantly (between 100 and 200 degrees) each year, parents may consider taking their child for a doctor's check-up.
Rapid progression and early onset of myopia may be an indication of other eye problems such as glaucoma - an eye disease that damages the optic nerve.
Any child with near-sightedness of more than 600 or 700 degrees is considered to have high myopia and it may lead to retinal detachment which usually results in blindness.
Can anything be done?
Asia's big cities will have to grapple with adult populations that have a high risk of developing high myopia. Getting kids to spend more time outdoors may help delay the onset of myopia for the young ones.
This article was first published in.