Light and health (part 1)

This paper discusses how the effect of light is related to health, wellbeing and diseases, of both a mental and physical nature. This not only concerns the optimisation of vision and the visual performance range, but also the «creation of knowledge» as a harbinger of consciousness. Since most of the sensory stimuli that reach our brain are of a visual nature, this means that the processing of information inputs is mainly a visual activity. This processing and the associated visual behaviour is predominantly done in a neural way through the «visual system» and hormonally through the «non􏰀visual system». These processes are explained and the associated research results, some of which have not yet been published, are presented. Results that predominantly concern the visual processes of perception also show the significance they would have if they were actually implemented. This also applies in particular to the «non􏰀visual system», in which the hormonal components that are influenced by light, i.e. serotonin and melatonin, are considered in conjunction with the circadian rhythm with regard to the implementation of daylighting and artificial lighting systems.