Myopia is experiencing an epidemic rise across the world, most dramatically among younger people (college educated and high school graduates) in East and South Asia where the prevalence has reached almost 100 percent in some demographics.1-6
Myopia is now one of the leading causes of vision impairment and blindness in the world.7 The prevalence of myopia has increased steadily during the last half of the 20th century and into the 21st century in most parts of the world,1,8-10 and is estimated to affect 50 percent of the world’s population by 2050 (Figure 1).1,8-11
The increasing prevalence of myopia has emerged as a global health concern because of sight-threating pathologies like myopic macular degeneration, choroidal neovascularization, cataract, and glaucoma associated with high myopia.12
Despite creating a major health burden, the exact mechanisms of myopic eye growth and its progression, particularly in the juvenile population, remain unknown.13
Hyperopic eyes of human infants and of infant monkeys made hyperopic with negative trial lenses experience coordinated growth, resulting in longer eyes and a refractive trend toward emmetropia (emmetropization).12,14 Juvenile myopia can be considered a failure of emmetropization or a possible reactivation of the emmetropization mechanisms in later childhood in response to chronic hyperopic defocus produced by habitual near viewing and accommodative lags.15
The second hypothesis could reflect eyes successfully adapting to the modern (near) environment. The high prevalence of myopia among populations that spend a lot of time doing near vision tasks (school children, high school and college students, and those in religious seminaries) further support the hypothesis that hyperopic defocus (central or peripheral) generated by accommodative lags during near work could stimulate eye growth (Figure 2).16-18
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