Effects of optical radiation on man

Abstract

Optical radiation (ultraviolet, visible and infra-red) produces many effects upon living matter. Seeing is of course the most important, but it is only one of the effects. UV-radiation has the widest effect, as a consequence of its photons rich in energy, though its proportion in the radiation of natural and artificial sources is relatively low compared with the proportions of the visible and the infra-red wavelength range. Visible radiation not only stimulates vision but acts physiologically and psychologically via the eye and the skin upon the endocrine glands, the vegetative nervous system, and upon the whole organism. Infra-red radiation acts in most cases by raising the temperature. In national and international committees effort is made to measure and calculate the actinic effects of optical radiation. (German standard DIN 5031 and CIE TC-1.7 (Actinic effects of optical radiation)). The illumination levels desirable from a photobiological point of view correspond with illumination levels obtained by experiments where a large number of observers have been asked to assess subjectively the lighting conditions.