Thursday, February 2

Childhood myopia: to blame for screens or a few hours outdoors?

The myopia It is a global problem that has not stopped growing in recent decades. Estimates indicate that one in four people all over the world is myopic.

And it doesn’t look like the trend is going to reverse: a study conducted in 2016 by Australian scientists predicted that by 2050, half of humans will suffer from this condition.

In this sense, experts highlight the importance of paying attention to childhood myopia. Especially since this problem often starts at school, and even before, depending on the type of myopia in question, and its early detection and treatment are essential to prevent myopia from advancing.

But the issue is also relevant because in recent years the increase in cases of childhood myopia has been very pronounced. From 2016 to the present the incidence of myopia in children has increased by 17%according to the last according to a demographic studypublished in September by the European University of Madrid and the Alain Affleou Foundation.

Signs of myopia in childhood

Myopia is a problem that occurs when the distance between the front and back of the eyeball is greater than normal. Consequently, distant images do not converge on the retina (as they should) but in front of it, and therefore they look blurry.

Nearby images, on the other hand, are seen correctly. On the other hand, there are two types of myopia: the simple and the pathological or magna.

The simple one generally appears at school age, at first as a small alteration, which becomes more accentuated with children and generally stabilizes at the end of development.

The pathological, meanwhile, begins earlier; it is often detected around four years of age. It is very pronounced from the first moment, and is related to major eye injurieswhich usually manifest after the age of fifty and can lead to glaucoma, cataracts and loss of vision.

That is why ophthalmological controls are essential in children from an early age. Usually, from three or four years of age They are already able to respond in consultation and collaborate with the specialist to determine their visual acuity.

Such checks are essential, especially when there are signs that the child has difficulties seeing far away. For example, yes frowns or winks when you have to observe and focus on distant objects.

Children with myopia also “may be more clueless and show less interest in activities that require good distance vision”, such as certain sports or games, explain experts from the Fernández-Vega Ophthalmological Institute.

For the same reasons, these children sometimes have a more withdrawn character and they are more book lovers or other activities that do not require seeing well in the distance, and also frequently express that they are tired or have a headache.

Screens and other possible causes

Among the causes of myopia it is undeniable that there is a genetic component. In fact, according to another demoscopic study, Children’s X-ray of Myopia in Spain (2016-2020), in half of the cases of children with myopia, one of the parents suffered from the same ailment. And in 30.9% of cases both suffered from it: the father and the mother.

But genetic inheritance does not explain the increase in the number of children with myopia. So what is it for? The reasons are not clear. It is known, however, that there are some facts related to this increase.

Traditionally, activities that involve focusing the vision closely for long periods of time have been identified as responsible for myopia: reading and, in recent times, the use of electronic devices with screenssuch as computers, phones and tablets.

Different studies –one of the last, from 2018, carried out by scientists in the United Kingdom and based on data from almost 68,000 men and women – found that people with a higher level of education are much more likely to suffer from myopia. This could be due to passing more time readingboth on paper and on screens.

A worked The previous one, from 2015, also stated that tasks that involve seeing closely for long periods of time increase the risk of myopia, something that could be seen during the COVID-19 pandemic. For this reason, he recommended “developing strategies to reduce the impact” of this kind of tasks on children.

The importance of sunlight

However, other reviews, like this one that uses files from the Cochrane Libraryargue that more studies are needed to establish the evidence of this association with screens.

even others works have supported for several years a hypothesis that points in another direction: the main cause of the increase in childhood myopia would be the Little time children spend outdoors.

Because the outdoor activities would reduce the incidence of myopia? Well, because the sunlight could lead to a eye development that artificial light -very different from natural light, although we do not notice it clearly with the naked eye- would not achieve it. This is how the ophthalmologist Rubén Pascual explains it in the Blog of his Ocultaris Project.

In addition, adds the specialist, “there could be an indirect variable, such as a sedentary lifestyle causing myopia and physical activity preventing it.” In this case, reading or displays they would not be causes of myopiabut activities associated with it due to the fact that, in general, they are carried out indoors and not outdoors.

According to Infant Radiography of Myopia in Spain (2016.2020), 38% of children spend less than 1.6 hours per day exposed to sunlight; 44% do it between 1.6 and 2.7 hours a day, and only 18% do outdoor activities for more than 2.7 hours each day.

Of course, the lockdown and other restrictions during the COVID pandemic had a negative impact on the possibilities to perform tasks outdoors.

But this possible benefit – preventing nearsightedness – is an incentive for children to spend more time away from homeif possible doing physical activity, which is also essential for their development.

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