Nursery Lighting May Not Increase Risk of Nearsightedness
March 8, 2000 (Lake Tahoe, Calif.) -- Parents concerned about whether night-lights are safe will be reassured by two studies published in Nature this week. The new research contradicts a study that appeared in the science journal last May implicating nighttime lighting in the bedroom of children under age 2 as a risk factor for myopia or nearsightedness.
Both new studies found that myopia occurred just as often in infants who had slept in the dark as it did if they had slept with a light on. Another important finding was that there was a link between the use of light at night and whether the parents had myopia.
This is significant, because children of myopic parents are more likely to develop nearsightedness later in life. In other words, having a nearsighted parent is the risk factor -- not whether a light in the children's bedroom is on while they're sleeping.
"Parents should light their nursery in a way that they're comfortable with and not worry about that decision," Karla Zadnik, OD, PhD, tells WebMD. Zadnik was the lead researcher of the Ohio State study involving more than 1,200 school children and their parents.
She found that about 18% of the children in her study group developed myopia around the age of 10. After analyzing questionnaires completed by the parents, Zadnik found no significant difference in myopia incidence between those children who slept under three different lighting conditions as infants and toddlers. However, Zadnik says, "Nearsighted parents say, 'Yes, we use night-lights.' It may be because they don't see as well at night or they're more insecure about how they see at night."
Researcher Jane Gwiazda, PhD, of the New England College of Optometry study, also in Nature, tells WebMD that she also looked at the parent's vision problems as well as asked them to answer questions about lighting in the bedrooms of their children when they were infants. Her results were very similar to those of Zadnik. "I feel very confident in saying there is no association between nursery lighting and the development of myopia. Parents should not worry about turning on a light at night. They should be comfortable with whatever conditions they need to have in the child's bedroom."