Myopia causes: Is your child at risk?

November 13, 2019

Causes of myopia in kids

Parents - especially those who are short-sighted and had to wear glasses in childhood - often worry about the causes of myopia and the possibility that their children are also destined to be short-sighted. If you feel identified, try not to worry too much.

Myopia is a common refractive error, easily treatable with contact lenses as well as glasses, and is not necessarily hereditary. On the other hand, the fact that the child is short-sighted does not usually affect his academic performance or cause any delay. In fact, there is evidence that short-sighted children tend to perform better in school, compared to peers with normal eyesight.

What causes myopia in children?

While the exact reason why some children become short-sighted and others do not is well known, it seems that inheritance is a factor, but not the only one. In other words, if both parents are short-sighted, there is a higher risk that their children will be too. However, it is not possible to predict who will become short-sighted by simply studying the ancestry of the family.

In my case, my parents and my two older brothers have perfect vision. I am the only one in the family that is short-sighted. Imagine yourself. When I was little I loved to read (I still love it); To my brothers, not so much. Some researchers think that fatigue from focusing, from excessive reading or from holding a book too close to the eyes for extended periods of time can increase the risk of myopia in children, although no one knows for sure.

Although the cause (or causes) of myopia remain a mystery, researchers have recently discovered something about the progression of myopia that is very interesting: it is possible that conventional glasses and contact lenses indicated for years to correct the Myopia actually increases the risk of making it worse!

Many of these researchers are studying new lens designs to see if they can develop contact lenses or glasses that can control myopia and stop or slow their progression in children.


How to reduce the risks of myopia in your child

This may sound simplistic, but perhaps one of the best things you can say to your child to reduce the risk of myopia is "Go play outside!" A number of recent studies have found that spending more time outdoors can help prevent or reduce the progression of myopia in children. Among them:

  • In the Sydney Study on myopia, Australian researchers evaluated the effect of time spent outdoors on the development and progression of myopia among children aged 6 and 12 randomly selected in 51 Sydney schools. 12 years who spent more time outdoors had less myopia than others, after the two-year period of the study, even after adjustment for the amount of reading performed, myopia of parents and ethnicity. Children who performed the Most short-range tasks and spent the least amount of time outdoors had the highest average amount of myopia.

  • In Taiwan, researchers evaluated the effect that outdoor activity during recess had on the risk and progression of myopia among elementary school students. Children who participated in the one-year study were 7 to 11 years old. years old and were selected at two nearby schools in a suburban area of ​​southern Taiwan.

    A total of 333 children from one of the schools were encouraged to leave during recess, while 238 children from the other school did not participate in a special “out of class recess” (ROC) program. At the beginning of the study there were no significant differences between the two groups of children in relation to age, sex, and prevalence of myopia (48% versus to 49%).

    But after a year, there were fewer new cases of nearsightedness in children at the school where recess was encouraged outside than those found in school children who did not encourage outdoor activity at recess (8.4 % versus 17.6%) There was also a significantly lower average progression of myopia among children who were already short-sighted in the ROC group, compared to the group that spent more time in indoor recess (-0.25 diopters [D] per year versus -0.38 D per year) .The study authors concluded that outdoor activities during elementary school recesses have a significant protective effect against the risk of myopia among children who are not yet short-sighted and reduce the progression of myopia among short-sighted students

  • Researchers from Denmark published a study on the effect of daylight available at different seasons of the year on the development of myopia among Danish schoolchildren. The risk of myopia was determined by measuring axial elongation (from front to bottom) from the eyes of children in the different seasons of the year. The increase in the axial length of the eye is related to increasing myopia.

    The amount of daylight changes substantially with the seasons in Denmark, and ranges from almost 18 hours per day in summer to only seven hours per day in the winter months In winter (when children had access to the least amount of daylight hours), the average growth of the axial length of their eyes was significantly greater than in summer, when exposure to outdoor sunlight was greater ( 0.19 mm versus 0.12 mm).

  • A group of researchers from the United Kingdom evaluated the results of carefully designed studies on the effect of time spent outdoors on the development and progression of myopia among 10,400 children and adolescents.The researchers calculated a 2% decrease in the risk of developing myopia for every additional hour children spend outside per week. "This equates to an 18% reduction for each additional hour of exposure per day," they said.

    Compared to children with normal vision or farsightedness, children with myopia spent an average of 3.7 hours a week less outdoors, they added. No particular activity was related to reducing the possibility of myopia. It was just about being outside instead of inside. Likewise, no correlation was found between the appearance of myopia and a tendency to perform more tasks at close range, such as studying.

    The researchers said more studies are needed to determine which factors related to the outdoors are the most important, such as increased use of distance vision, reduced use of near vision, physical activities and exposure to natural ultraviolet light.

The final message

Given the previous research, it is a great idea to encourage your children to spend more time outside (and leave cell phones and other electronic devices at home or in their pockets). This habit may reduce the risk of becoming short-sighted, or delay the progression of your current level of myopia. Better yet: join them to share quality time outdoors!