<em>Caffeine Free: Blue Light Makes People Alert at Night
</em>01 February 2006

There's much more than meets the eye to how we perceive light, researchers have learned in recent years. The latest revelation: blue light helps fend off drowsiness in the middle of the night.

A small study of 16 volunteers found that exposure to short-wavelength light, or blue light, perked them up immediately.

"Light exposure to this system, particularly blue light, directly reduces sleepiness,” said Steven Lockley of the Brigham and Women's Hospital. “Subjects exposed to blue light were able to sustain a high level of alertness during the night when people usually feel most sleepy, and these results suggest that light may be a powerful countermeasure for the negative effects of fatigue for people who work at night."

The study, sponsored by National Space Biomedical Research Institute, is detailed in the Feb. 1 issue of the journal Sleep.

More over at <a href="http://www.livescience.com/humanbiology/060201_blue_light.html" target="new" >Live Science</a>