Symbolism, Imagery, Allegory
"I See," Said The Blind Man
Sophocles certainly wasn't shy about the motif of sight vs. blindness. If you've got way too much time on your hands (or want to write an awesome essay) go through the play and highlight words like "see," "sight," "vision," "eyes," and "blind." Since this motif is symbolic of the pursuit of "knowledge," you can go ahead add that word, along with terms like "oracle," "truth," "prophecy," and "Apollo," since he's the god that represents all these ideas.
The Oracle of Shmoop predicts that your highlighter will run out of ink, and your book will end up looking like a neon patchwork quilt.
Though this motif of seeing and not seeing is laced throughout the beginning of the play, it first becomes crystal clear when the prophet Teiresias hobbles on stage. If one of Sophocles' ancient audience members missed the irony in this episode, he must've visited the wine stand a few too many times.
Teiresias is literally blind, but he can see clearly the horror that is Oedipus' past, present, and future. Oedipus' eyes work just fine, but unfortunately he's completely blind to the dreadful fate the gods have placed upon him. The doomed king's ignorance on this key matter is made even more ironic by the fact that he was made famous for his keen insight, by solving the riddle of the Sphinx.
In fact, Oedipus gets peevish with Teiresias and calls into question his powers as a "seer" because he failed to see through the Sphinx's mind-game:
This tricksy beggar-priest, for gain alone Keen-eyed, but in his proper art stone-blind. Say, sirrah, hast thou ever proved thyself A prophet? When the riddling Sphinx was here Why hadst thou no deliverance for this folk? And yet the riddle was not to be solved By guess-work but required the prophet's art; Wherein thou wast found lacking; neither birds Nor sign from heaven helped thee, but I came, The simple Oedipus; I stopped her mouth. (389-398)
Oh, the irony.
When Oedipus finally sees the terrible truth of his life, Sophocles hammers home his metaphor by having the king stab out his own eyes. Oedipus says he does this because he can no longer look on the horrors that his unwitting actions have created.
With this most famous of gougings (at least until Game of Thrones brought them back into vogue) Oedipus literally becomes the thing he's always metaphorically been: blind. At the end of the play, Oedipus becomes symbolic of all of humanity, stumbling forward through a dark and unknowable universe.
