Optimizing light and lighting for health, recent advances and recommendations

Description

Light is an important regulator of human sleep, mood, circadian rhythms, performance and hormone secretion. Lighting solutions that combine such non-visual responses to light with light’s visual effects as to foster human comfort, health and well-being are frequently denoted as integrative or human-centric lighting. To drive light’s visual and non-visual effects, the human eye uses five photoreceptor inputs (rods, S/M/L-cones, ipRGCs). Especially the input of the melanopsin-based photoreceptor (the ipRGC) is an important determinant of non-visual responses to light. In this presentation I will (i) explain the basics of circadian photoregulation and photoreception; (ii) introduce the metrology from international standard CIE S026:2018 to describe light for its non-visual effects; (iii) discuss some examples that demonstrate how useful this metrology is for solid state lighting technology, field applications and lab experiments; (iv) provide initial guidance for healthy daytime, evening and nighttime light exposures in day-active people.