I'm not a doctor, but we know about the negative effects of light on sleep. Our species evolved with little nighttime light, and we know the mechanism by which our circadian rhythms are tricked by artificial light.
Most sleep experts (including pediatric sleep experts) recommend blacking out your room, removing all electronics, etc.
Perhaps an expert in this area can chime in, but I don't think light during sleep is positive.
It’s interesting to think about the origin of the many ancient myths and legends about human behavior during full moons (i.e. insane behavior, sleepwalking, criminality,accidents, etc) and the possibilities of even that small amount of light (as generated by a full moon) having an affect on human behavior and emotion, especially during times of our evolution when the alternative was a nearly pitch black environment.
It did, and it actually does have a circadian effect. But it has much less illuminance than most artificial light sources. That's what I mean when I say "little nighttime light."
Given the wonders of dark adaptation of the human eye (https://en.wikipedia.org/wiki/Adaptation_(eye)#Dark_adaptati...), does that really matter? In my experience, the full moon is almost bright enough to comfortably read normal black on white printed text.
Many of the mechanisms for light impacting biological functions show a clear dose-response relationship - fewer photons hitting the retina leads to less effect.
As a rough estimate, one decade (10x) of the eye’s light adaptation, at most, comes from aperture variation - the pupil expanding and contracting. The rest comes from intensity-driven modification of the sensing and image processing systems in the eye - rods that are completely saturated with signal above a few dozen lux become the primary sensors in very low light.
In other words - just because the moon provides enough light to see and even read doesn’t mean that it will cause insomnia.
Most sleep experts (including pediatric sleep experts) recommend blacking out your room, removing all electronics, etc.
Perhaps an expert in this area can chime in, but I don't think light during sleep is positive.