Extensive information on light exposure and health is given on the web site:
Another excellent information source is:
Video reviewing topic of circadian rhythms and light exposure:
It takes a bit of patience to get through the early part of this video, as they get the slides to display properly.
In recognition of the International Year of Light, the International Dark-Sky Association presents an On Air Hangout on Light and Health with Dr. Richard Stevens and Dr. Mario Motta. Saturday, February 28 2015