Visual problems are on the increase worldwide, especially among children and adolescents, as the World Health Organization (WHO) has just revealed. No country is immune to this trend, which concerns ophthalmologists.
Will we all be condemned to wearing glasses in the near future? Ophthalmologists are seeing now more young patients who are affected by nearsightedness, even though their parents do not have vision problems.
The first to speak of an “epidemic” was Australian scientist Ian Morgan, who published a study in The Lancet in 2012, in which he estimated the prevalence of myopia among Asian youth to be nearly 90%. In Japan, China and South Korea, nine out of ten students wear glasses.
Since then, the proportion has not decreased; on the contrary, as the World Health Organization noted in its first global vision report on 8 October. More than 2.2 billion people worldwide are now visually impaired or blind. Developing countries, where health care is less good, are particularly affected. But the rich countries must not be overlooked: refraction problems like myopia, hypermetropia, presbyopia, and astigmatism are on the increase.
2.6 billion nearsighted people
A recent global meta-analysis shows that the number of children and adolescents with myopia is expected to increase by 200 million between 2000 and 2050. For example, by 2020 more than 2.6 billion people will be suffering from myopia, the WHO warns. Europe is already affected. According to a major epidemiological study carried out in 15 countries and published in 2015, the prevalence of myopia has risen from 18% to 23.5% in just over a generation – with the understanding that researchers have defined myopia here with a diopter of -0.75%.
Today’s children look at more screens and read closer than ever before. This causes the overuse of the muscle that distorts the lens.
How do you explain this explosion? “Today’s children look at more screens and read closer than ever before. This causes the contraction of a muscle that distorts the lens. To prevent this, the eye will automatically increase in size and cause myopia,” explains Thomas J. Wolfensberger, medical director and head of the Jules-Gonin Ophthalmology Hospital. The other explanation relates to natural light, which has to stimulate the eye cells that control the growth of the eye. Because young people spend more time indoors, they are less exposed to it and therefore have to wear glasses.
To avoid this vicious circle, Thomas J. Wolfensberger recommends that children spend at least one hour a day away from home – a measure of common sense that has become mandatory in Korean schools in recent years. This effort is not only intended to prevent the children and adults from wearing glasses. Above all, it could enable them to escape from more serious diseases: “Myopes are more prone to diseases such as cataract, glaucoma, retinal detachments, or macular diseases,” said Gabriele Thumann.
When a child is at risk of very high myopia, ophthalmologists can prescribe low doses of atropine drops to slow down the growth of the eyeball. But it can happen that children with a vision of -8 at 8 years of age could go to -12 at -13 years of age later, which is a real handicap. For her, this treatment should under no circumstances be a blank check to leave children permanently indoors, glued to their screens, without sunlight.