DEVICE, METHOD AND SYSTEM FOR BIOLOGICALLY BALANCED LIGHTING

A lighting device providing emitted light with an adjustable correlated color temperature (CCT) is described. The lighting device comprises one or more light emitters and a controller configured to independently control each of the one or more light emitters. Each respective light emitter is configured to provide one or more spectral components of the emitted light, wherein the emitted light comprises a respective photoreceptor-to-photopic luminance activation ratio for each ocular photoreceptor class corresponding to an intended CCT of the emitted light. The respective photoreceptor-to-photopic luminance activation ratios comprise each of (a) a melanopsin (i)-to-photopic-luminance activation ratio; (b) a rhodopsin (R)-to-photopic-luminance activation ratio; (c) a long-wavelength sensitive opsin (L)-to-photopic-luminance activation ratio; (d) a middle-wavelength sensitive opsin (M)-to-photopic-luminance activation ratio; and (e) a short-wavelength sensitive opsin (S)-to-photopic-luminance activation ratio. Each of (a); (b); (c); (d); and (e) are within a defined range of a respective activation ratio of a blackbody radiator with the intended CCT. The emitted light may have variable excitation ratios for the five photoreceptors prompting a biological response matching that of a different blackbody radiator with changes that are invisible to the eye or difficult to perceive.