Conventional energy sources are polluting and limited, and so it is essential to use sources that are less aggressive with the environment. This premise is being transversely implemented in the field of lighting but in response to varied and sometimes contradictory interests. The development of lighting devices based on solar radiation, or daylighting, is an indispensable objective, as is the use of artificial lighting sources that respect the environment. We present the main aspects of important technologies studied for the different fields of lighting, such as optical systems, design techniques, and lighting elements—light guides and those encompassed within nonimaging optics, as well as their implementation and application in various areas such as office lighting, libraries, and museums. We show that an efficient energy strategy in the design of a lighting system not only saves energy and is economic but also produces beneficial and important effects in other nonmaterial aspects of human life, such as well-being, productivity, and heritage conservation.