Human Centric Lighting
The most appropriate definition for human centric lighting comes from the CIE (Commission Internationale de l’Eclairage) through the term “Integrative Lighting”: “Lighting especifically designed to produce a beneficial physiological and/or psychological effect upon humans“ (including both, visual and non-visual effects).
First important detail is that light and lighting are different terms. I define lighting as the “art and science of delivering light”. Second, the non-visual effects of light and lighting go far beyond the pure visual function to see, and we have to account for intensity and spectrum (not only color perception), time/dose, time of day, directionality, the environment (architectural spaces) and the beholder (age, health condition, allostasis and stress). We are vibrational beings, with a clock function in each of our cells, being light our main entrainer and zeitgeber for our circadian rhythmicity that is key for our health and our functional psycho-physiology.
Exposome
A few years ago, in 2005, the cancer epidemiologist Christopher Paul Wild introduced the term “Exposome” to better understand the causes of dis-ease (not necessarily illness). According to the US Centers for Disease Control and Prevention (CDC), “genetics has been found to account for only about 10% of diseases, and the remaining causes appear to be from environmental causes”. A strong statement that should make us think seriously about our life conditions and habits, and perhaps not that much about our genetic inheritance. The Exposome can be defined, following Wild, as the study of the lifetime exposures of an individual, in relationship with health. We were conceived and we have evolved as daylight creatures. This means that light is one of the main factors that affects our life, during our lifetime. Exposure to ultraviolet (UV) and to infrared (IR) has been researched in relationship with our health, and this is pending related to visible light. Most of the artificial light sources do not follow the patterns of the sun, our natural source of light. The disbalances in spectrum emission and the differences in light intensity, much lower indoors than outdoors, together with the lack of darkness, cause disturbances in our psycho-physiology, being sleep the main one, with associated comorbidities that directly affect our health and quality of life.