As the editors at Erasmus University Medical Center in the Netherlands suggested, “young children may be more sensitive to environmental myopic triggers.” A previous eye study in children in Sydney, Australia also found that only the younger ones who became myopic were more Spending time near work than being outside in daylight.
May 4, 2021, 6:45 p.m. ET
Although many people have long believed that excessive reading promotes myopia in children, the current belief is that spending too much time indoors has the greater effect and likely explains an obvious link between close work or screen time and myopia.
Dr. Neil M. Bressler, an ophthalmologist with the Johns Hopkins Medical Institutions, said the high intensity of outside light has an important impact on the shape of the eye, which in turn affects whether images are seen clearly.
To be sharp, rays of light in an image must converge on the retina. In myopic eyes, convergence occurs in front of the retina and a corrective lens is required to redirect incident rays so that distant objects are in focus.
Most children are easily born farsighted. Your eyes are shaped like partially deflated spheres, causing images to converge behind the retina. But as they get older, their eyes elongate to form a sphere so images can converge right on the retina. However, if at some point the stretch does not stop, the eyes become more oval and the images converge in front of the retina, the definition of myopia. Outdoor light stimulates the release of dopamine, which can slow the elongation of the eye, said Dr. Bressler.
Although myopia is increasing worldwide, the epidemic is raging in East and Southeast Asia, where 80 to 90 percent of high school children are now nearsighted.
Concerns about the prevalence of myopia go beyond the growing need for glasses, contact lenses, or, for those who can and can afford, laser treatment to redirect images by changing the shape of the cornea. In general, later in life, people with myopia are more likely to develop visual disorders such as cataracts, glaucoma, and degeneration of the macula, the center of the retina.