HUMAN FACTORS, 1981,23(1),65-85 Lighting for the Elderly: A Psychobiological Approach to Lighting

The present paper reviews the role of illumination in shaping the indoor environment of the elderly person. The approach is that lighting has a twofold impact on the individual. One is as a source of information about the environment, i.e., visual, and the other is photobiologi-cal through the skin or photoreceptor. The visually lighted environment is reviewed, discussing first the physiological changes that occur during the aging process, then the effect of aging on visual performance, and finally the importance of qualitative factors in assessing the adequacy of an illuminated environment for the elderly. Special attention is given to application problems in lighting for the elderly, i.e., excessive brightness differences, discomfort glare, veiling reflections, and the importance of color and the spectral power distribution of the light source. The advantages of a full-spectrum light source which simulates natural sunlight for indoor illumination is discussed in light of recent research. The biologically lighted environment is reviewed in terms of the potential role that indoor illumination can play in regulating important biochemical processes in the elderly popula-tion, i.e., neuroendocrine control, vitamin Da synthesis, immunologic mechanisms, and cardiovascular regulation