The study of the activating effects of light on living organisms

of, relating to, or caused by the energy or momentum of light or other electromagnetic radiations / of, or relating to photodynamics

By means of, or with regard to, photodynamics.

Relating to photodynamics.

(medicine) A treatment for some forms of cancer and some skin disorders, involving the use of photosensitive chemicals, and controlled and directed laser beams.

plural of photodynamic therapy