Myopia: How the traditional understanding of nearsightedness is failing our kids

An emerging consensus is forming that a decreased amount of time spent outdoors is significantly increasing the risk of myopia among school-aged children.

Conventionally, myopia or nearsightedness was once considered solely a genetic issue. Probably because it would be rare to find a myopic child without one or both parents having the condition themselves. As myopia was deemed to be caused solely by genetics, other contributing factors i.e. behaviour and lifestyle influences, and discussions of their preventive measures have grossly been overlooked.

As a result, rates of myopia slowly but steadily increased over the first three-quarters of the 20th century. Recently, however, cases of myopia have spiked around the world, and an emerging consensus is forming that a decreased amount of time spent outdoors is significantly increasing the risk of myopia among school-aged children.

Is myopia an epidemic?

In 2010, 28% of the world’s population was affected by myopia. Studies show that by 2050, the prevalence of myopia globally is predicted to be 50% of the world’s population. Over the last 50 years, East Asian countries have seen the largest increase in paediatric myopia cases, increasing from roughly 25 percent of the population to more than 80 percent.

Here in Canada, a study by the University of Waterloo’s Centre for Ocular Research and Education published a decade ago showed similar trendlines. Out of a group of 166 children from southwestern Ontario, myopia was found in 17.5 percent of those examined.

Most concerning, 34.5 percent of the myopic children had not received corrective treatment, meaning they likely hadn’t had an eye exam, and glasses were not prescribed.

Related question: Can myopia be treated or cured?

Is myopia a big deal?

The sharp increase in the number of children who have myopia is concerning because the higher the level of myopia, the higher the chance of eye diseases such as glaucoma and retinal detachment.  Therefore, early recognition and treatment can help prevent serious problems later in life.

How do we protect our children from myopia?

A comprehensive strategic approach to prevent and manage myopia needs to be in place. The priority should be to prevent the onset of myopia (h). Next, if a child becomes myopic, high myopia  should be prevented. And if a child becomes highly myopic, we want to prevent pathological myopia and all of its complications.

Preventive measures of myopia onset:

Tip 1: Go outside: Outdoor activities are proven to be effective measures of preventing myopia. Trials in Taiwan and China have found that 40 to 80 minutes of extra outdoor time during the day reduced myopia incidence in schoolchildren by up to 50%. Two hours daily has been stated as the preferred amount of time for one to spend outside.

Why it works The difference between the intensity of light indoors and outdoors is a great factor here. Especially during noon, going out in bright light is proven to be beneficial. Another factor here is, while being outdoors, children have more opportunities to see the horizon and distance.

Tip 2: Bring light indoors: As children spend a significant amount of time in classrooms, bringing ample light indoors is another effective preventive measure. This can be done by the usage of skylights, proximity to windows, and filtering infrared lights.

Tip 3: Limit Near Work: Taking regular periodic breaks from near work (i.e. using handheld devices, reading) has been strongly suggested.

Myopia Control

Once a child is myopic, some effective treatments like specialized myopia control glasses and contacts, as well as medicated eye drops, can slow down the progression of myopia. Your Optometrist can help find the treatment that is the best fit for your child.

When should my child see an optometrist?

Children should be seen at age 6 months, then yearly starting at age 3. Along with lifestyle and behavioural measures, making eye exams a yearly tradition can help prevent, detect and manage the progression of myopia.

In Ontario, OHIP covers one annual comprehensive eye exam for all children until age 19. Follow-up appointments are also covered. To find an Optometrist in Ontario, visit

Dr. Angela Yoon, HBSc, OD
University of Waterloo School of Optometry and Vision Science, 2001 Graduate

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