from journal SLEEP
Light from a smartphone, leaving the TV on overnight or other sources of artificial light may be messing with our health. Less than one-half of five hundred people in a study by Northwestern University consistently slept in total darkness. Dr. Minjee Kim and her colleagues set out to see if this light pollution had anything to do with the chronic health problems faced by older adults, such as diabetes and cardiovascular disease. The study, in the journal SLEEP, did not determine if light caused health issues or if existing health problems caused people to leave a light on. But, restoration of a natural light-darkness cycle, they say, improves a variety of health conditions.