photic (adj.)youdaoicibaDictYouDict[photic 词源字典]
1843, "pertaining to light;" 1899, "pertaining to the parts of the ocean penetrated by sunlight," from Greek phot-, comb. form of Greek phos "light" (related to phainein "to show, to bring to light;" see phantasm) + -ic.[photic etymology, photic origin, 英语词源]
photyoudaoicibaDictYouDict
"A unit of illumination equal to one lumen per square centimetre", Early 20th century: from Greek phōs, phōt- 'light'.
photismyoudaoicibaDictYouDict
"A hallucinatory sensation or vision of light", Late 19th century: from Greek phōtismos, from phōtizein 'to shine', from phōs, phōt- 'light'.