title: Near-work activity, night-lights, and myopia in the Singapore-China study.
abstract: OBJECTIVE
  To investigate the relationship among near-work activity, night-lights, and myopia in schoolchildren in Singapore and Xiamen, China.
  
  
  METHODS
  The refractive error and ocular dimensions of 957 Chinese schoolchildren aged 7 to 9 years in Singapore and Xiamen, China, were determined using cycloplegic autorefraction and A-scan ultrasound biometry. Information on near-work activity (number of books read per week, reading in hours per day) and night-light use before age 2 years was obtained.
  
  
  RESULTS
  The prevalence rate of myopia was 36.7% (95% confidence interval [CI], 33.0%-40.3%) in Singapore and 18.5% (95% CI, 14.0%-23.1%) in Xiamen, China. The crude odds ratio (OR) of higher myopia (at least -3.0 diopters) for children who read more than 2 books per week was 3.50 (95% CI, 2.15-5.70). In a multivariate logistic regression model, the OR of higher myopia for children who read more was 2.81 (95% CI, 1.69-4.69), adjusted for age, night-light use, parental myopia, and country, whereas there was no association between night-light use before age 2 years and higher myopia (OR, 1.54; 95% CI, 0.92-2.58), after controlling for age, books read per week, parental myopia, and country.
  
  
  METHODS
  The ORs of higher myopia for children who read more and children who are exposed to night-lights before age 2 years.
  
  
  CONCLUSIONS
  Reading (number of books per week) may be associated with higher myopia in Chinese schoolchildren. However, night-light use does not seem to be related to higher myopia.
authors: Department of Community, Occupational, and Family Medicine, National University of Singapore, 16 Medical Dr, Singapore 117597, Republic of Singapore. cofsawsm@nus.edu.sg
authors: Seang-Mei
authors: SM
authors: Saw
authors: Ming-Zhi
authors: MZ
authors: Zhang
authors: Rong-Zhao
authors: RZ
authors: Hong
authors: Zhi-Fu
authors: ZF
authors: Fu
authors: Mei-Hua
authors: MH
authors: Pang
authors: Donald T H
authors: DT
authors: Tan
mesh_terms: D002648:Child; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006802:Human Activities; D006801:Humans; D008029:Lighting; D008297:Male; D009216:Myopia / Q000453:epidemiology* / Q000209:etiology; D016017:Odds Ratio; D015995:Prevalence; D011932:Reading; D012846:Singapore / Q000453:epidemiology; D014937:Work