Lighting simply made better: Providing a full range of benefits without much fuss

The effective application of lighting depends upon a definition of light that captures the full range of wavelengths to which the human retina is sensitive. The current definition of light, based upon the photopic luminous efficiency function, V(λ), does not. Rather, V(λ) is biased against short wavelengths that are important for some of the benefits that lighting can provide to people such as brightness perception and circadian regulation, thereby compromising the effective application of lighting. Neuroscience has revealed several visual and non-visual channels that emanate from the retina to different centers in the brain influencing our physiology and behavior. This research has also elucidated the spectral and the absolute sensitivities of these different neural channels. Since the definition of light and the many lighting standards do not reflect the neuroscience, they compromise the beneficial application of lighting. A new definition of light based upon the universal luminous efficiency function, U(λ), would be unbiased with respect to the full range of wavelengths to which the retina is sensitive. Coupled with scientific insight into the spectral and absolute sensitivities of the various neural channels, lighting can easily become more effective for delivering the benefits people expect.