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LRC News

Summer 2008
Circadian Math: One plus One Doesn’t Always Equal Two

Subjects wore special LED glasses developed for the studyLike a wristwatch that needs to be wound daily for accurate time-telling, the human circadian system—the biological cycle that repeats approximately every 24 hours—requires daily light exposure through the eye’s retina to remain synchronized with the solar day.

In a new study published in the June issue of Neuroscience Letters, LRC researchers demonstrated that when it comes to the circadian system, not all light exposure is created equal.  The findings have profound implications for exploring how lighting can be used to adjust our bodies’ clocks, and they could redefine the way lighting is manufactured, according to Mariana Figueiro, lead author of the paper and LRC assistant professor. Learn more…

About the Lighting Research Center

The Lighting Research Center (LRC) is part of Rensselaer Polytechnic Institute of Troy, N.Y., and is the leading university-based research center devoted to lighting. The LRC offers the world's premier graduate education in lighting, including one- and two-year master's programs and a Ph.D. program. Since 1988 the LRC has built an international reputation as a reliable source for objective information about lighting technologies, applications, and products. The LRC also provides training programs for government agencies, utilities, contractors, lighting designers, and other lighting professionals. Visit

Contact:lrcnewsletter@rpi.eduPhotos & Graphics:Dennis Guyon
Editor:Mary CimoWeb Production:Joann Coffey
Contributing Writers:Jennifer Taylor, Mary Cimo
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