Time spent outdoors in childhood is associated with reduced risk of myopia as an adult

Abstract

Myopia (near-sightedness) is an important public health issue. Spending more time outdoors can prevent myopia but the long-term association between this exposure and myopia has not been well characterised. We investigated the relationship between time spent outdoors in childhood, adolescence and young adulthood and risk of myopia in young adulthood. The Kidskin Young Adult Myopia Study (KYAMS) was a follow-up of the Kidskin Study, a sun exposure-intervention study of 1776 children aged 6–12 years. Myopia status was assessed in 303 (17.6%) KYAMS participants (aged 25–30 years) and several subjective and objective measures of time spent outdoors were collected in childhood (8–12 years) and adulthood. Index measures of total, childhood and recent time spent outdoors were developed using confirmatory factor analysis. Logistic regression was used to assess the association between a 0.1-unit change in the time outdoor indices and risk of myopia after adjusting for sex, education, outdoor occupation, parental myopia, parental education, ancestry and Kidskin Study intervention group. Spending more time outdoors during childhood was associated with reduced risk of myopia in young adulthood (multivariable odds ratio [OR] 0.82, 95% confidence interval [CI] 0.69, 0.98). Spending more time outdoors in later adolescence and young adulthood was associated with reduced risk of late-onset myopia (≥ 15 years of age, multivariable OR 0.79, 95% CI 0.64, 0.98). Spending more time outdoors in both childhood and adolescence was associated with less myopia in young adulthood.

The Prevalence of Myopia in Children in Spain: An Updated Study in 2020

“…Similar results were found by Deng et al [ 42 ]. Furthermore, Lingham et al [ 43 ] also found that spending more time outdoors in childhood is associated with a reduced risk of myopia in young adulthood. That is, spending more time outdoors in both childhood and adolescence is associated with less myopia in young adulthood.…”

The effect of transverse ocular magnification adjustment on macular thickness profile in different refractive errors in community-based adults

“…Between 2015 and 2019, when they were 25–30 years of age, participants were invited to attend a comprehensive eye examination as part of the K-YAMS. The purpose of that eye examination was to explore whether these early educational interventions influence myopia development [ 45 ].…”

Transient Eye Shortening During Reading Text With Inverted Contrast: Effects of Refractive Error and Letter Size

“…There are two main options: (1) the visual information necessary for the retina to emmetropize the eye is altered or insufficient, or (2) the myopic retina undergoes functional changes early in myopia development which compromises correct retinal growth control, despite appropriate visual input. In favor of the first assumption is that emmetropization is affected by restrictions of the spectral composition of light (i.e., tree shrews 3 ; rhesus monkeys 4 ; chickens 5 ), to lower average illuminances (i.e., human 6 ; rhesus monkeys 7 , 8 ; mice 9 ). It was also proposed that spatial features of the visual environment, like the “greenness of the residential area” 10 or changes in the spatial frequency spectra can affect emmetropization.…”

“…In favor of the first assumption is that emmetropization is affected by restrictions of the spectral composition of light (i.e., tree shrews 3 ; rhesus monkeys 4 ; chickens 5 ), to lower average illuminances (i.e., human 6 ; rhesus monkeys 7 , 8 ; mice 9 ). It was also proposed that spatial features of the visual environment, like the “greenness of the residential area” 10 or changes in the spatial frequency spectra can affect emmetropization.…”