• epidemiology
• myopia

Uncorrected or undercorrected refractive error is the leading cause of preventable vision impairment in the world today, with an estimated 75 million cases of low vision due to refractive problems.¹ Because refractive error is a major cause of avoidable blindness, the World Health Organization has named refraction as one of the five priorities for Vision 2020—the Right to Sight.² Not all blindness associated with refractive error is avoidable as high myopia can lead to choroidal atrophy and subsequent myopic retinal degneration.³

People with myopia are more likely than people with hypermetropia to have undercorrected refractive errors.⁴ Although debate continues about the relative contribution of genetics and environment in the development of myopia, …