Exposing people to short flashes of light while they’re sleeping could provide a fast and efficient method of preventing jet lag, according to a study by researchers at the Stanford University School of Medicine.

“This could be a new way of adjusting much more quickly to time changes than other methods in use today,” said Jamie Zeitzer, PhD, assistant professor of psychiatry and behavioral sciences.

Zeitzer is senior author of the study, which was published online Feb. 8 in the Journal of Clinical Investigation. The lead author is Raymond Najjar, PhD, a former postdoctoral scholar at Stanford now at the Singapore Eye Research Institute.

Researchers led by Zeitzer have been working on developing an optimal technique for using light exposure to help people adjust more quickly to changes in their sleep cycles. Current light-therapy treatments for sleep disturbances include sitting in front of bright lights for hours at a time during the day, which allows you to transition your body clock to a new time zone in small steps prior to taking a trip.

Night light

In an earlier study, Zeitzer and his colleagues found that light therapy works best at night because the body’s circadian rhythms, which control sleep cycles, are more sensitive to light at night, even through closed eyelids.

In the latest study, Zeitzer and Najjar found that short flashes of light at night are more effective than continuous light exposure and could further speed up the process of adjusting to a different time zone before a trip.

The transfer of light through the eyes to the brain does more than provide sight; it also changes the biological clock. A person’s brain can be tricked into adjusting more quickly to disturbances in sleep cycles by increasing how long he or she is exposed to light prior to traveling to a new time zone.

After arriving in a new time zone, the body will eventually adjust on its own, but at a slow pace of about one hour a day. Meanwhile, jet lag, which occurs because your body’s clock is still synced to your original time zone, can cause fatigue, lack of alertness, a general feeling of malaise and sometimes gastrointestinal problems.

Biological ‘hacking’

Light therapy is designed to speed up the brain’s adjustment to time changes. By conducting light therapy at night, the brain’s biological clock gets tricked into adjusting to an awake cycle even when asleep. It’s a kind of “biological hacking” that fools the brain into thinking the day is longer while you get to sleep, Zeitzer said.