A central processing center for immigrant children and families has overhead lighting that stays on around the clock, reports The New England Journal of Medicine.

It is critical for their health and safety that children be allowed to sleep in the dark at night and be exposed to bright outdoor light during the day. Exposure to constant light not only interferes with their ability to obtain the sleep they need, especially during development, it is also one of the most powerful means of disrupting the endogenous circadian rhythms that regulate circadian clocks throughout the body, which depend on retinal exposure to a periodic light–dark cycle to remain in synch with the Earth’s 24-hour day.