The Collaborative International Dictionary
Photology
Photology \Pho*tol"o*gy\, n. [Photo- + -logy: cf. F. photologie.] The doctrine or science of light, explaining its nature and phenomena; optics.
Wiktionary
photology
n. 1 A branch of physics that deals with light or the study of light and its effects. 2 That science concerned with the production of light and energy, especially regarding therapeutic applications.