The Collaborative International Dictionary of English v.0.48:

Photic \Pho"tic\ (f[=o]"t[i^]k), a. [Gr. fw^s, fwto`s, light.]
   Of or pertaining to light; specifically, relating to the
   production of light by the lower animals.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

photic
    adj 1: of or relating to or caused by light