Optical

google

ref

late Middle English: from French optique or medieval Latin opticus, from Greek optikos, from optos ‘seen’.

wiktionary

ref

optic +‎  -al

etymonline

ref

optical (adj.)

1560s, "relating to or connected with the science of optics; pertaining to vision," from optic + -al (1). Of abstract art, from 1964. In astronomy, in reference to double stars that appear so only because they lie in the same line of sight from earth, by 1868. Optical illusion is attested by 1757. Related: Optically.