Manchester Study Links Brighter Daytime Light to Deeper Sleep in 89 Adults

3 articles · Updated · SciTechDaily · Jul 16

Eighty-nine adults tracked for more than 500 days showed that brighter, steadier daytime light was linked to earlier sleep, earlier waking and more deep sleep early in the night.
Melanopic light sensors, consumer sleep trackers and daily diaries let University of Manchester researchers test in everyday life what lab studies had already suggested about light resetting the body clock.
More regular light exposure — with fewer swings between dim and bright conditions — was also associated with healthier sleep timing and deeper early-night sleep, a stage tied to memory and recovery.
Poorer nights widened the gap between how participants thought they slept and what wearables recorded, while the findings add to concerns that dim indoor days and overly bright evenings may undermine health.