Nearsightedness is at epidemic levels – and the problem begins in childhood
Some even consider myopia, also known as nearsightedness, an epidemic.
- Some even consider myopia, also known as nearsightedness, an epidemic.
- In the United States alone, spending on corrective lenses, eye tests and related expenses may be as high as US$7.2 billion a year.
- To answer that question, first let’s examine what causes myopia – and what reduces it.
How myopia develops
- Optometrists have learned a great deal about the progression of myopia by studying visual development in infant chickens.
- Just like in humans, if visual input is distorted, a chick’s eyes grow too large, resulting in myopia.
- The more time we spend focusing on something within arm’s length of our faces, dubbed “near work,” the greater the odds of having myopia.
Outside light keeps myopia at bay
- A 2022 study, for example, found that myopia rates were more than four times greater for children who didn’t spend much time outdoors – say, once or twice a week – compared with those who were outside daily.
- In another paper, from 2012, researchers conducted a meta-analysis of seven studies that compared duration of time spent outdoors with myopia incidence.
- The odds of developing myopia dropped by 2% for each hour spent outside per week.
What’s driving the epidemic
- Globally, a big part of this is due to the rapid development and industrialization of countries in East Asia over the last 50 years.
- Around that time, young people began spending more time in classrooms reading and focusing on other objects very close to their eyes and less time outdoors.
- This is also what researchers observed in the North American Arctic after World War II, when schooling was mandated for Indigenous people.
Treating myopia
- Fortunately, just a few minutes a day with glasses or contact lenses that correct for blur stops the progression of myopia, which is why early vision testing and vision correction are important to limit the development of myopia.
- People with with high myopia, however, have increased risk of blindness and other severe eye problems, such as retinal detachment, in which the retina pulls away from the the back of the eye.
- The chances of myopia-related macular degeneration increase by 40% for each diopter of myopia.
Andrew Herbert receives funding from NSF.