This article refers to "moderate" (100 lx) light exposure - this amounts to an overhead light on in the room for the entire duration of sleep.
I would say an overhead light is a significant amount of light, but wonder how low the threshold is for sleep disruptions. Living in an urban environment, there's a non-negligible amount of ambient light that makes its way in. I don't use a set of blackout curtains, but I know several friends that say it makes a real difference.
I would say an overhead light is a significant amount of light, but wonder how low the threshold is for sleep disruptions. Living in an urban environment, there's a non-negligible amount of ambient light that makes its way in. I don't use a set of blackout curtains, but I know several friends that say it makes a real difference.