A Wired news report examines how scientists are naturally changing the circadian rhythms of astronauts in space to improve sleep using new light bulbs.
Sleep is regulated in part by melatonin, a hormone the body produces when the eye detects darkness. “Light is the most important cue for resetting the clock,” neuroscientist Steven Lockley says. In a replica of the ISS crew quarters, photobiologists installed color- and brightness-adjustable LEDs, and volunteers came in for light baths at different intensities. The results: The lower the light, the more melatonin in volunteers’ blood, potentially improving their sleep.