Book excerpt: Building Physics: Lighting, Seeing in the Artificial Environment deals with basic principles of lighting as used in architecture, in building maintenance, and in an artificial environment. The book starts with the process of how humans see; the interaction of the eye and mind; and the effects of fatigue, visual disorders, and age. The phenomena of light are then discussed — how light behaves and how it is measured. Light and light waves beyond the visible spectrum are explained scientifically as being part of the electromagnetic spectrum within the 400 to 760 nm ranges. The different light sources are identified as daylight and artificial lights, with many types of lamps under the latter. As regards artificial lighting, a lighting fitting has two functions: redistributes luminescence properly and provides a suitable receptacle for the lamp. The requirements when using artificial or natural light in an exterior or interior setting are enumerated. The book also explains the specifications of the amount of light and how this amount is calculated. Interior lighting, both from artificial and natural sources, is comprehensively discussed, including issues such as discomfort glare, reflected glare, design and aesthetics, lighting requirements in different kinds of buildings, and flammability properties. The text also tackles exterior lighting including decorative floodlights, lighting for tunnels and underpasses, and special problem areas. Architects, engineers, electricians, interior designers, lighting technicians, environmentalists, and readers with interest in home decor will find this book useful.