Introduction to photobiology.

Photobiology is the study of the local and systemic effects of incident radiation on living organisms. Solar radiation is made up of ultraviolet, visible and infrared radiation. Ultraviolet radiation is made up of UV-C, UV-B, and UV-A. Sun exposure can lead to sunburn, tanning, vitamin D production, photoaging, and carcinogenesis. Phototherapy is the use of nonionizing radiation to treat cutaneous disease. Various types of artificial light sources are used for photo testing and phototherapy.