Myopia, or nearsightedness, has surged dramatically in recent decades, turning from a common vision issue into what many experts now describe as a global epidemic. By 2050, it’s projected that roughly half the world’s population will need glasses or contacts to see clearly at a distance—a sharp increase from just 23% in 2000. The financial toll is staggering too, with billions spent annually on vision correction and eye care, particularly in countries like the United States.
But what’s behind this rapid rise in myopia? Is it genetics, lifestyle, or something else? As a vision scientist studying how we perceive and process visual information, I’ve come to understand that this epidemic is less about DNA and more about behavior—especially the way children’s eyes develop in response to their environment.
How Nearsightedness Develops: Lessons from Baby Chicks
One of the more unusual but enlightening ways scientists study myopia is by observing baby chickens. Researchers fit chicks with tiny helmets equipped with lenses that manipulate how their eyes perceive focus. When these young birds experience blurred vision, their eyes grow excessively, causing myopia. This growth is progressive—blur begets eye growth, which causes more blur, in a vicious cycle.
The parallels to humans are striking. Just as in chicks, when human eyes focus on blurry images or close objects for extended periods, the eyes tend to elongate, making distant objects appear even blurrier. This process explains why myopia tends to worsen over time, especially in children.
Near Work and the Growing Epidemic
Recent large-scale studies surveying children and their parents reinforce a clear pattern: the more time kids spend focusing on objects close to their faces—be it books, screens, or drawing pads—the higher their risk of developing myopia. This “near work” behavior, while often educational or recreational, seems to overstimulate the eye’s focusing mechanism in a way that encourages excessive eye growth.
Interestingly, it’s not just new technology like smartphones and tablets to blame. Even traditional activities like reading can contribute if done excessively without breaks or outdoor time.
The Protective Power of Outdoor Light
There’s a silver lining: exposure to natural sunlight appears to counteract the progression of myopia. A 2022 study found that children who spent little time outdoors had myopia rates over four times higher than those who played outside daily. Moreover, kids who spent more than three hours daily doing close-up activities were four times more likely to be nearsighted compared to those who limited such activities to an hour or less.
Meta-analyses of multiple studies back this up, showing that every additional hour spent outside per week decreases the chance of developing myopia by about 2%. The bright, natural light outdoors seems to signal the eyes to regulate growth properly, preventing excessive elongation.
Why Now? The Role of Rapid Industrialization and Schooling
Why has myopia skyrocketed only recently? The answer lies partly in societal changes over the past 50 years, especially in East Asia. Rapid urbanization and industrialization brought shifts in childhood lifestyles: more classroom time spent focusing on books and screens, coupled with less outdoor play.
Historical examples support this. Among the Inuit in the North American Arctic, myopia was rare before the 1950s. After formal schooling became mandatory post-World War II, rates soared to around 70% by the 1970s.
Though Western countries have also seen increases, they’re nowhere near the levels seen in places like China, Japan, and Singapore, where intense academic pressure and reduced outdoor activity prevail.
The Long-Term Impact and Importance of Early Intervention
The full effects of this epidemic will unfold over decades. Myopia doesn’t just cause blurry vision; severe cases increase the risk of serious eye diseases like retinal detachment and macular degeneration—leading causes of blindness.
Thankfully, early detection and correction can halt or slow myopia’s progression. Simple measures like prescription glasses or contact lenses reduce the eye’s need to grow excessively. That’s why many countries, including the UK, China, and most US states, mandate early vision screenings for children.
Practical Advice for Protecting Young Eyes
Changing habits in today’s digital age can be challenging, but some steps can help protect eyesight:
- Limit prolonged near work: Encourage breaks during reading, homework, or screen time to reduce eye strain.
- Spend time outdoors daily: Aim for at least an hour outside in natural light, ideally more.
- Combine screen use with outdoor activities: If children use devices, let them do so outside when possible.
- Regular eye exams: Early detection and correction of myopia are key to preventing progression.
Conclusion: A Vision for Healthier Eyes and Lifestyles
The rise in nearsightedness isn’t just a medical issue; it’s a signal about how modern childhood environments diverge from what our eyes evolved to handle. Understanding the behavioral roots of myopia empowers parents, educators, and health professionals to take steps toward reversing this trend.
By balancing near work with outdoor play and emphasizing early eye care, we can help children maintain healthy vision—and potentially curb the myopia epidemic before it blurs our collective future.
Andrew Herbert is a vision scientist specializing in visual perception. This article is adapted from The Conversation, an independent nonprofit dedicated to sharing expert knowledge.
