Eyes use light to reset biological clock

April 25, 2008 at 11:52 PM   |   Comments

BALTIMORE, April 25 (UPI) -- A U.S. study said the eye uses light to reset the biological clock through a mechanism that is different from the ability to see.

The findings from biologists at John Hopkins University could have implications for people suffering from seasonal affective disorder and insomnia, the university said in a release.

"It seems that even if individuals have normal sight, they might be having a malfunction that is contributing to their inability to detect light, which can adversely affect their biological clocks," said Samer Hattar, an assistant professor of biology.

The study, published online in the journal Nature, said tests on mice showed that there are two distinct pathways for the two different aspects of light detection -- image-forming and non-image-forming.

Hattar and his team said daily exposure to natural light enhances memory, mood and learning. He said people should get out in the sun for at least a little while each day and avoid very bright lights at night.

"The idea is to keep your internal rhythm in sync with the cycle of the sun: exposure during the day when the sun is out, less exposure at night, when the sun is down, so to speak," Hattar said.

Topics: John Hopkins
© 2008 United Press International, Inc. All Rights Reserved. Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.
Recommended UPI Stories
Featured UPI Collection
Celebrity Couples of 2014 [PHOTOS]

Celebrity Couples of 2014 [PHOTOS]

Most Popular
Tropical storm Karina looks like the number 9 from space
Study explains why ER nurses do what they do
Tech industry All Stars developing 'Star Trek'-style communication badges
Researchers dig up earliest evidence of snail-eating
Neanderthals and humans interacted for thousands of years
Trending News