Optometry and Vision Science
Myopia and Its Association with Near Work, Outdoor Time, and Housing Type among Schoolchildren in South India
In this comprehensive assessment of environmental associations with refractive status among schoolchildren in India, outdoor time was the key modifiable risk factor associated with myopia rather than time spent on near work.
PURPOSE
This study aimed to investigate the environmental risk factors associated with myopia among adolescent schoolchildren in South India.
METHODS
Children in grades 8 to 10 from 11 schools in Tamil Nadu, South India, underwent eye examination and risk factor assessments through a modified version of the Sydney myopia questionnaire. Time spent on near work and outdoors was analyzed after division into three groups based on tertiles. Mixed-effects logistic regression was performed to assess the factors associated with myopia.
RESULTS
A total of 3429 children (response rate, 78.4%) provided both questionnaire and refraction data. The mean (standard deviation) age was 14 (0.93) years with an equal distribution of sexes. Myopia was present among 867 children (noncycloplegic spherical equivalent refraction, ≤−0.75 D). Refraction was not associated with near work tertiles (P = .22), whereas less time outdoors was associated with higher myopic refractions (P = .01). Refraction shifted toward increased myopia with an increase in the near-work/outdoor time ratio (P = .005). Children living in apartment housing had a higher prevalence of myopia compared with other types of housing (P