The contrast between light and dark, and blindness and sight plays a large role throughout Oedipus Rex. The light and dark imagery that pervades the play is used as a metaphor for Oedipus's spiritual blindness. The darkness represents his inability to see the truth about his life. .
Oedipus Rex is a play full of paradox. The imagery of sightedness and blindness highlight the contrasts between the characters. Tiresias, a prophet, who can see the future and knows what will happen to Oedipus, is physically blind. During the exchange between Tiresias and Oedipus near the beginning of the play, constant reference is made to Oedipus" sight and Tiresias" blindness. The irony here lies in the fact that Tiresias" sight is far greater than Oedipus"; despite his physical handicap, Tiresias can see the truth about who Oedipus is and what will happen in his life. Oedipus, however, is unwilling to listen to Tiresias and ignores the truth of his words; speaking to Tiresias he says, referring to Tiresias" blindness, "Living in perpetual night, you cannot harm me, not any man else that sees the light." Oedipus himself is too blind to see that he is truly the one living in darkness; his past and his future both shrouded in obscurity.
These images are mirrored in Oedipus" relationship with the city of Thebes itself. Oedipus comes to Thebes a hero; solving the Sphinx's riddle and setting Thebes free from her curse. In dealing with the Sphinx, Oedipus shows his mind's capacity for brightness. "From you, bird-lore and god-craft were silent. Until I came- I, ignorant Oedipus, came- and stopped the riddler's mouth, guessing the truth by mother-wit, not bird-lore." Oedipus takes pride in his intelligence, bragging about the cleverness with which he answered the Sphinx. Later, in talking to Tiresias, Oedipus is faced with riddles more pertinent to himself; and this time his mind is dark, unwilling or unable, because of Oedipus" pride, to accept the implications of Tiresias" words.