Myopia, also known as nearsightedness or shortsightedness, is common among children of all ages. Five percent of preschoolers, 9% of elementary-age children, and 30% of adolescents in the United States have myopia. And the numbers are rising. Researchers predict that by 2050, about half the people in the world will have myopia. This makes it important for parents to understand this vision issue.
Why Is Myopia on the Rise?There are lots of theories about why more children are becoming nearsighted. We know that when children play outside more, their risk of myopia drops.
Outdoor time is good for vision in several ways. When your eyes are exposed to sunlight, your body releases a chemical called dopamine. Researchers believe that dopamine affects the retina, a layer of cells at the back of the eye that receives light through the cornea and sends signals to the brain. The dopamine slows down lengthening of the eye (axial growth). When the eye lengthens into an oval shape rather than the round shape it should be, light rays don’t focus on the retina as they should, causing nearsightedness.
Sunshine also provides vitamin D. Some studies show that people with myopia have lower vitamin D levels than people without the condition. Researchers still need to learn more to see if there is a connection between the vitamin and myopia.
Finally, being outside gives kids a bigger picture. More and more of kids’ lives, including school, takes place on electronic devices, forcing their eyes to focus closely on small, bright screens. And it isn’t just electronics: Research shows that most of our activities are literally within arm’s reach, whether it’s screen time, reading, or other activities. Being outdoors allows kids to focus on things at different distances – a “workout” for the eye.
