Actually, it is a classical word, meaning 'with beautiful eyes'. opos is in the genitive, so that's where the meaning comes from.

Actually, I think whoever coined the term was unaware of the word you linked to in LSJ. (The entry is short with no citations.) I think the neologist simply took the Greek roots for beautiful and eye and the ending -ia and ran with it.

Ceci n'est pas un seing.