Photobiological safety

Abstract

Photobiology is a scientific field that involves biology, physics and chemistry in order to study the effects of optical radiations on living organisms. Lighting systems are sources of artificial optical radiations used primarily to provide light to the human eye in order to enable visual processes in the absence of enough daylight. The first photobiological effect of a visible light source is vision itself. Photobiological safety refers to the undesirable effects of optical radiations on human tissues, especially the skin and the eye. These effects have several possible causes, according to the exposed tissue, the wavelength of the incident radiation, the intensity of the exposure and the duration of the exposure. According to these parameters, the effects can be temporary (reversible), or permanent in the case of severe exposures. This chapter presents an overview of the knowledge concerning the photobiological safety of LEDs and products using LEDs such as solid-state lighting (SSL) products.