サーカディアン(概日)リズムとメラトニンの役割等については、以下をご参照ください:

http://ja.m.wikipedia.org/wiki/%E3%83%A1%E3%83%A9%E3%83%88%E3%83%8B%E3%83%B3

http://ja.m.wikipedia.org/wiki/%E6%A6%82%E6%97%A5%E3%83%AA%E3%82%BA%E3%83%A0%E7%9D%A1%E7%9C%A0%E9%9A%9C%E5%AE%B3

http://en.m.wikipedia.org/wiki/Melatonin

http://en.m.wikipedia.org/wiki/Melanopsin

http://en.m.wikipedia.org/wiki/Circadian_rhythms

http://en.m.wikipedia.org/wiki/Circadian_rhythm_disorder

科学的研究の例です:

Amplitude Reduction and Phase Shifts of Melatonin, Cortisol and Other Circadian Rhythms after a Gradual Advance of Sleep and Light Exposure in Humans Derk-Jan Dijk, Jeanne F. Duffy, Edward J. Silva, Theresa L. Shanahan, Diane B. Boivin, Charles A. Czeisler 2012

Exposure to Room Light before Bedtime Suppresses Melatonin Onset and Shortens Melatonin Duration in Humans Joshua J. Gooley, Kyle Chamberlain, Kurt A. Smith, Sat Bir S. Khalsa, Shantha M. W. Rajaratnam, Eliza Van Reen, Jamie M. Zeitzer, Charles A. Czeisler, Steven W. 2011

Effect of Light on Human Circadian Physiology Jeanne F. Duffy, Charles A. Czeisler 2009

Efficacy of a single sequence of intermittent bright light pulses for delaying circadian phase in humans Claude Gronfier, Kenneth P. Wright, Richard E. Kronauer, Megan E. Jewett, Charles A. Czeisler 2009

Intrinsic period and light intensity determine the phase relationship between melatonin and sleep in humans Kenneth P. Wright, Claude Gronfier, Jeanne F. Duffy, Charles A. Czeisler 2009

The Impact of Sleep Timing and Bright Light Exposure on Attentional Impairment during Night Work Nayantara Santhi, Daniel Aeschbach, Todd S. Horowitz, Charles A. Czeisler 2008

Short-Wavelength Light Sensitivity of Circadian, Pupillary, and Visual Awareness in Humans Lacking an Outer Retina Farhan H. Zaidi, Joseph T. Hull, Stuart N. Peirson, Katharina Wulff, Daniel Aeschbach, Joshua J. Gooley, George C. Brainard, Kevin Gregory-Evans, Joseph F. Rizzo, III, Charles A. Czeisler, Russell G. Foster, Merrick J. Moseley, Steven W. Lockley. 2007

High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light. Lockley SW, Brainard GC, Czeisler CA. 2003

Sensitivity of the human circadian pacemaker to nocturnal light: melatonin phase resetting and suppression Jamie M Zeitzer, Derk-Jan Dijk, Richard E Kronauer, Emery N Brown, Charles A Czeisler 2000

Phase-shifting human circadian rhythms: influence of sleep timing, social contact and light exposure J F Duffy, R E Kronauer, C A Czeisler 1996

Exposure to bright light and darkness to treat physiologic maladaptation to night work. Czeisler CA, Johnson MP, Duffy JF, Brown EN, Ronda JM, Kronauer RE. 1990