Short Flashes Of Light During Sleep May Prevent Jet Lag

A cure for jet lag?

A recent study confirms that exposing people to short flashes of light, during sleep, is more effective than using continuous light, according to research. Continuous lights are used as a therapy to prevent circadian rhythm disruptions.

As cited in the Stanford Medicine website, Jamie Zeitzer, Ph.D., assistant professor of psychiatry and behavioral sciences, said that this method could be a new way to adjust more quickly to time changes, compared to the new ways used today.

Zeitzer, a senior author of the research, along with Raymond Najjar, Ph.D., a former postdoctoral scholar at Stanford now at the Singapore Eye Research Institute, found out that short flashes of light at night time speeds up the process of adjusting to a different time zone before a trip. This is because the transfer of light, from the eye to the brain changes the body’s clock.

The length or the duration of which the brain is exposed to the light before traveling to a new time zone can easily be tricked the brain into adjusting quickly, to the disturbances of a sleep cycle, the report said.

The body follows a normal phase of adjusting to a new time zone, but on a lower pace. With jet lag, on the other hand, the body’s internal clock still coordinates with your original time zone. This is the reason people experience fatigue, insomnia, cognitive impairment, mood swings, like irritability, dizziness, and other discomforts.

Zeitzer added that the light therapy is designed to speed up the brain’s adjustment to time changes. He invoked that this method or biological hacking” fools the brain into thinking the day is longer while you get to sleep.

It was found out that a 2-millisecond sequence light flashes, like a camera flash, at 10 seconds apart resulted in a nearly two-hour delay in sleep onset.

Why the short flashing lights works? According to the Zeitzer, this involves physiology. “The first is that the cells in the retina that transmit the light information to the circadian system continue to fire for several minutes after the stimulus — in this case, flashing light — is no longer there,” he said. “The second is that the gaps of darkness between the light flashes allow the pigments in the eye that respond to the light to regenerate — that is, go from an inactive form that cannot respond to light to an active form that is able to respond to light” (

He said that flashing light therapy used at night could also be a great way of helping other people, who work in constantly changing time schedules, like the medical residents, night –shift workers and even sleepy truck drivers.

The research was published online Feb. 8 in the Journal of Clinical Investigation, with support and grants from the National Heart, Lung and Blood Institute and the Department of Veterans Affairs Sierra Pacific Mental Illness Research, Education and Clinical Center.



White, T. Study finds possible new jet-lag treatment: Exposure to flashing light, Feb. 08, 2016.


Amabelle Equio,  Ph.D candidate in Nursing at Silliman University, Health, Fitness, Medical Writer, Photography Enthusiast.

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