This is a good question. One of the main themes of Sophocles's Oedipus Rex is the idea of blindness and sight.
Oedipus was physically able to see, but when it came to weightier matters, such as his identity, he was blind. On the other hand, the seer was physically blind, but he was a man filled with wisdom and insight. His name was Tiresias.
Oedipus would not believe in Tiresias, but as the plot unfolded, he was forced to deal with the truth of who he was and what he did. The irony is, at the end of the tragedy, Oedipus blinds himself when he saw most clearly.
Here are some works spoken by Tiresias concering Oedipus:
"Blind who now has eyes, beggar who now is rich,
he will grope his way toward a foreign soil,
a stick tapping before him step by step."
Again Tiresias says, "How terrible to see the truth when the truth is only pain to him who sees!"
Finally, as the Theban tragedies continues, by the time Oedipus makes it to Colonus, he becomes a holy man.
infact at the begging of the play it was Terisias who was the seer though physically blind yet spiritually a man, full of sight.
anyhow, at the end we find Oedipus has taken the place of the old Terisias.he himself has become a seer without eyes.this insight/knowledge/enlightenment comes through endless sufferings which ultimately lead him to the realization of some bigger truth.He has gone through the philosophy of knowledge or life thats why he knows the tru nature of th relationship between man and god.therefore,regardless of his physical eyes, he is equal to a seer now
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