Researchers have just confirmed the hypothesis that the lack of natural light is an important trigger in the development of myopia. Up to 80% of the younger generations in Asia and nearly 50% in Europe today have poor distance vision.
A new study, published in Nature Genetics, has just deciphered the role of light in the development of myopia. The causes of myopia are both genetic and environmental.
Concretely, the researchers have identified 161 new genes responsible for the development of myopia, the vast majority of which triggers this eye disease when they do not receive enough light while being in high demand. “This supports the hypothesis that insufficient sunlight is an important trigger in the development of myopia,” the team notes.
When natural light arrives at the level of the eye, it is received by the pupil and especially the lens (a component of the eye) to the cells of the retina which line the back of the organ. For clear vision, the light rays should meet as close as possible behind the retina. In the case of myopia, this junction of rays takes place in front of the retina. They say the eye is too long. Thus, distant objects appear blurry. There are varying degrees of myopia, depending on the position at which the radiation converges in the eye.
Transmission of the neurotransmitter GABA
In 2016, in a scientific article appeared in the review Nature Communication, the Consortium for Refractive Error and Myopia (CREAM) had already described 9 new genetic variants that contribute to the development of myopia.
To identify them, the researchers analyzed some thirty studies bringing together more than 50,000 participants around the world. These 9 genetic variants are associated with proteins involved in the transmission of chemical signals in the eyes. One of them plays a particularly important role in the transmission of the neurotransmitter GABA, and many studies have shown that this gene is overactivated in myopic people.
80% of the younger generations in Asia
Myopia, which is the most common eye disorder, has been on the rise in recent decades. Up to 80% of the younger generations in Asia and nearly 50% in Europe today have poor distance vision. A particularly worrying situation for people who suffer from severe myopia, because this eye pathology increases the risk of developing eye complications.
This is the largest genetic study ever conducted on myopia. The team evaluated data from more than 250,000 people in Europe, Asia and North America. “Sending your children to play outside for two hours every day in the light is the best way to prevent myopia,” concludes Norbert Pfeiffer, lead author of the study. Some countries like Taiwan have thus adapted schooling by adding time away from home. Myopia is said to decrease by 10% each year.
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