2023-07-18 16:43:14
Let’s look back almost a hundred years, to the time when our grandparents and great-grandparents were little. In 1928 it was published in the magazine Public Health Bulletin a work by several researchers that showed that only 3.8% of children between the ages of 6 and 14 in the United States were myopic. In contrast, 21.6% of them suffered from farsightedness. Almost fifty years later, in the 1970s, the prevalence of myopia in people between the ages of 12 and 17 rose to 25% and at the beginning of this century, almost 34%.
If we look at Asian countries, the growth is even more alarming, since in many countries in that region the percentages exceed 80% of the child and adolescent population. In Spain, a recent study carried out by AMIRES (Association of High Myopia with Retinopathies) showed that the number of children with myopia tripled between the second and sixth grades. And the estimate is that in 2050 half of the world’s population will be myopic.
Changes in lifestyle: a possible explanation
Something has changed a century ago for prevalence to have taken such an impressive leap. The relationship of myopia with genetics is evident: it is much easier to experience it if our parents suffer from it. And the greater the weight of this genetic predisposition the greater the myopia (if it is greater than 5-6 diopters it is considered magna or pathological).
This has not changed, but it has –and substantially– our habits: the distance at which we focus our eyes throughout the day. Our grandparents and great grandparents spent a lot of time looking from afar. They did not have the facility to study and, of course, they spent their leisure hours playing in the street, where everything is far away (think that, in optical terms, six meters is infinite).
It is true that the children of the last decades of the 20th century did spend a lot of time studying, but they continued to dedicate their free time to outdoor activities. And in the 21st century they already spend most of the day looking closely, both to study and to play.
For example, according to a 2021 meta-analysis, looking at mobile or tablet screens for many hours would increase the risk of myopia by 30% in people from 3 months to 33 years of age. And the percentage would skyrocket to 80% when excessive use of computers is added.
But let’s not make the mistake of blaming the radiation from the screens, but the distance at which these devices are used. In a certain way, for lovers of anthropology, perhaps we are only facing an adaptation of the human to the environment. Life is now lived up close.
Consequences (serious) of myopia
But what difference does it make to the diopters that my son has if with glasses or contact lenses it will be solved? It’s not that simple. Although in most cases myopia is a non-pathological vision defect, when it progresses excessively it can lead to associated pathologies such as retinal detachment, myopic maculopathies, optic nerve disorders or glaucoma. These diseases will appear mainly during adulthood, with the consequence of blindness in the most serious cases.
We cannot forget that pathological myopia is at the forefront of ailments in members of the Spanish National Organization for the Blind (ONCE). In addition, low vision has intangible effects on quality of life, such as dependence on optical correction and professional or sports limitations, which are more severe the further the disorder progresses.
What can we do?
In the last decade, different therapeutic interventions have been developed to try to minimize the growth of myopia in children. Currently there are drugs such as atropine, which are administered in the form of drops; contact lenses for night use -such as orthokeratology- and day use -such as peripheral blur lenses-; or even glasses with ophthalmic lenses that have proven their effectiveness.
Scientific evidence indicates that all these interventions present a reduction in the increase in myopia of between 35% and 60%. Their effectiveness has been proven, but the mechanism of action by which they reduce eye growth, which is the reason for the progression of the visual defect, is still not known with certainty.
In any case, check-ups with professionals such as ophthalmologists and opticians-optometrists are essential in childhood to be able to treat myopia properly and as soon as possible.
Perhaps the adult Manolito Gafotas of 2023 would be more myopic than a current child character, since he would benefit from one of the aforementioned treatments. And although in 2050 he would still be part of the myopic half of humanity, he would probably suffer less risk of eye complications from this unstoppable phenomenon of our times.
Juan Gonzalo Carracedo Rodríguez, Professor of Optometry and Vision University, Complutense University of Madrid. This article was originally published on The Conversation. Read the original.
This content was originally published on RED/ACCIÓN and is republished as part of the ‘Human Journalism’ program, an alliance for quality journalism between RÍO NEGRO and RED/ACCIÓN.
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