Do blue light glasses protect children's sleep?

What the evidence says

The idea behind blue light glasses is that light from bedtime screens can suppress the sleep hormone melatonin and delay sleep. There's good evidence that light itself, especially blue-toned light, affects children's melatonin and alertness at night. But it's a big leap from that to proving that glasses which filter blue light actually fix children's sleep.

The best available study directly testing this in kids is a small crossover trial of 39 Japanese schoolchildren wearing 40%-blocking glasses before bed. It found earlier bedtimes and reduced evening irritability, but melatonin levels themselves did not change, suggesting some other mechanism, or a placebo/behavioural effect, may be at play.

In adults, the picture is even messier: systematic reviews describe the trial evidence as inconsistent, with some studies finding modest benefits and a review of pooled trials finding roughly half showed benefits and half didn't. No major pediatric body such as the Canadian Paediatric Society, AAP, or CDC currently recommends blue light glasses as a sleep tool for children.

What these organizations do recommend, based on more consistent evidence, is simply limiting or avoiding screens for at least an hour before bedtime and keeping screens out of the bedroom. That's a more proven strategy than relying on special glasses.