I read with great interest the letter from Zadnik1
and the editorial2 discussing possible biases
and errors that could have influenced the results of the study by Quinn et
al3 in the May 13, 1999, issue of Nature. The authors reported a strong positive correlation
between night light exposure in children younger than 2 years and later development
of myopia. Accordingly, serious concerns have been raised about scientific
evidence of the causal relationship reported in this study. Thus, the advice
to avoid room lighting for sleeping children does not seem to be justifiable.
During the last 2 years, however, many newspapers and some ophthalmologic
journals recommended that parents avoid using night lights in their children's
bedrooms. Although the study by Quinn et al3
did not establish a casual link, it has been suggested that the absence of
a daily period of darkness during early childhood represents a risk in the
development of myopia.
Midelfart A. Association Between Light Exposure During the Night and Myopia in Children. Arch Ophthalmol. 2002;120(3):406-407. doi: