Near-work activity, night-lights, and myopia in the Singapore-China study.

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.