Sleep experts advise people to avoid turning on a light when getting up in the middle of the night for a drink, to use the bathroom or let the dog out. That's because light is absorbed by photoreceptors in the eye that trigger the suppression of melatonin, the hormone in the body that is released at night to help us sleep.
For people working night shifts, however, exposure to 20 minutes of bright light is used to fight drowsiness. A study released Monday at a major sleep research meeting found that millisecond flashes of bright light might work just as well to help workers stay alert. The study found even a two-millisecond pulse of bright light delivered once an hour led to significant improvements in self-rated alertness and performance on tests.
"We found it shocking that light exposure as brief as a few milliseconds could engender changes in alertness and brain wave activity," the lead author of the study, Jamie M. Zeitzer of Stanford University, said in a news release. "These results change the manner in which we think about the brain's capacity to respond to light."
The study was presented at the Associated Professional Sleep Societies meeting.
-- Shari Roan
Photo credit: Eric Boyd / Los Angeles Times