Introduction: Historical Vignettes from the Field of Photomedicine

The present handbook aims to cover the entire area of medical knowledge known as “photomedicine.” This field is concerned with two broad areas of medicine: (1) diseases caused by light and (2) the therapeutic applications of light known as phototherapy. The latter broad area can be further subdivided into five more-specialized applications of phototherapy: (i) ultraviolet phototherapy, (ii) photodynamic therapy (PDT), (iii) lowlevel laser (light) therapy, (iv) laser surgery and medicine, and (v) phototherapy for miscellaneous applications.