optic (adj.)

late 14c., optik, "of or pertaining to the eye as the organ of vision," from Old French optique, obtique (c. 1300) and directly from Medieval Latin opticus "of sight or seeing," from Greek optikos "of or having to do with sight," from optos "seen, visible," related to ōps "eye," from PIE root *okw- "to see." Meaning "relating to or pertaining to vision or sight" is from 1590s. Optics "eyes" is from 1640s; "formerly the learned and elegant term; afterwards pedantic, and now usually humorous" [OED].