Do Night Lights Cause Nearsightedness?

Attention guilty parents! If you've been chastising yourself for allowing your child to use a nightlight, take heart. Despite the widely held belief that nighttime light is harmful to young eyes, newer evidence shows this is not the case.

In 1999, researchers from the University of Pennsylvania released a study stating that "ambient light exposure during sleep at night in the first two years" greatly increased the chance of later nearsightedness. The report received an incredible amount of press, and parents everywhere took note. Less publicized were two later studies that proved the first incorrect.

The National Eye Institute, a division of the National Institutes of Health, gave funding to researchers at Ohio State University for further study. They tested 1,220 children in a variety of environments. What they found was that 20% of all children develop nearsightedness later in life, regardless of whether they slept in the dark as children, or whether they slept in a fully lit room. They discovered that nearsightedness in children was dependent on whether or not the child's parents were nearsighted –- something the University of Pennsylvania study failed to take into account.

A study by the New England College of Optometry in Boston agreed. Interestingly though, this study found that families with two nearsighted parents were more likely to use nightlights.

Nightmares are common in young children, as is fear of the dark. It's time to put to rest the notion that children must sleep in a pitch-black room. Of course, it's best to teach your kids that there's nothing to fear in the dark. But if you decide to give them a nightlight, there's no reason to feel guilty.