Abstract: Methods and apparatus for circadian lighting are disclosed. In particular, improved lighting is described in relation to a novel definition of an optimum relative circadian spectral sensitivity distribution (“Circadian Potency SSD”) with a peak sensitivity at approximately 470 nm-480 nm (preferable embodiments at 472 nm or 478 nm) with a full width at half maximum (“FWHM”) of approximately 50 nm which is skewed asymmetrically between approximately 440 nm and approximately 490 nm. Methods and approaches to determine the Circadian Potency of light sources from their spectral power distributions (SPD) and use the CircadianPotency SSD to optimize healthy circadian function under normal indoor and outdoor illumination conditions are described herein, and incorporated into various light sources, including white light sources, dimmable light sources, and daytime/nighttime light sources.

Abstract: Systems and methods for controlling environmental illumination relative to circadian function of individuals are provided. A method is provided for controlling the operation of light sources by assigning a circadian state to the individual based on received electronic information, extrapolating future circadian states based on the assigned circadian state, the assigned circadian state or the extrapolated future circadian states including at least a biological night state, and encoding machine-level control commands that control the operation of the light source for transmission to the light sources adapted for the biological night state by having circadian-significant attenuation along the circadian active wavelength range.

Abstract: Systems and methods for controlling environmental illumination relative to circadian function of individuals are provided. A method is provided for controlling the operation of light sources by assigning a circadian state to the individual based on received electronic information, extrapolating future circadian states based on the assigned circadian state, the assigned circadian state or the extrapolated future circadian states including at least a biological night state, and encoding machine-level control commands that control the operation of the light source for transmission to the light sources adapted for the biological night state by having circadian-significant attenuation along the circadian active wavelength range.