ABSTRACT
Optical radiation is an important environmental factor essential to normal human development and activity. Both insufcient and excessive exposure to optical radiation can cause many negative biological effects. Optical radiation is a natural component of solar radiation and can be produced articially by electrical and technological sources. Electrical sources are used in many industrial processes, medical treatments, and in the cosmetic industry. Optical radiation is also emitted into the environment as a by-product of processes like welding and plasma cutting and by hot objects like blast furnaces (Wolska et al. 2001).
