I would suggest you look at this document if you are interested in LED safety, specifically the part about Blue Light Hazard.
http://www.lightingeurope.org/...les/CELMA_ELC_LED_WG(SM)011_ELC_CELMA_position_paper_optical_safety_LED_lighting_Final_1st_Edition_July2011.pdf
Blue light hazard is a known problem with LED lighting. It is a topic that you can Google. Note that medically it is the evolution of a physiological experience called Purkinje Shift.
Regards,
Lou N