Myopia is a common affliction (one in four adult Americans is near-sighted¹), and juvenile-onset myopia is believed to be due to a combination of genetic and environmental factors². Results from animal experiments indicate that light cycles may affect the development of myopia^{3, 4}, and Quinn et al. claim to have extended these to humans⁵. They reported a strong association between childhood myopia and night-time lighting before the age of two: there were five times more children with myopia among those who slept with room lights on than in those who slept in the dark, and an intermediate number among those sleeping with a dim night-light⁵. However, we have been unable to find a link between night-time nursery lighting and the development of myopia in a sample of schoolchildren.

1. College of Optometry, Ohio State University, Columbus, Ohio 43210-1240, USA
2. School of Optometry, University of Alabama, Birmingham, Alabama 35294-0010, USA
3. College of Optometry, University of Houston, Houston, Texas 77204-6052, USA
4. Southern California College of Optometry , Fullerton, California 92831, USA
5. for the CLEERE Study Group

Correspondence to: Karla Zadnik^1,5 e-mail: Email: zadnik.4@osu.edu