Full Ironic, almost tragic, how the sense of sight is the most sought after of all the senses when in fact it is the weakest. Oedipus Rex proved that in an irrepressible chaos caused by arrogance, vanity, and impatience.
Teiresias, though blind, saw beyond the physical world and beyond time. He saw through Oedipus’ true identity, saw the course of his future, and, perhaps, even the path that would lead Oedipus to the terrifying future. Teiresias, as opposed to what many believe, didn’t motivate Oedipus towards his prophesy. The act of Oedipus summoning Teiresias to tell him the identity of his real parents was a part of the formation of his fate. It was only for Teiresias to see what Oedipus was creating. Teiresias said:
How dreadful knowledge of the truth can be
When there’s no help in truth! I knew this well…
Let me go home Bear your own fate, and I’ll
Bear mine. It is better so: Trust what I say. 
The blind seer Teiresias represents fate not the manipulation of it as many argue. It was proven with a self-fulfilling prophecy unravelling throughout the story.
On the other hand, Oedipus, with fully functioning eyes were blind to reason, just and humility. He was already a Prince of Corinth, regarded and respected by his people and loved like a real child by his parents. He had an entire kingdom destined to be his living with parents who loved him no less than their real son. Yet, he look passed it. He fixed his gaze a truth he doesn’t even see. Oedipus, the seeing man who is supposed to symbolize freewill, was blinded by his own greed.
Vision is a metaphor for knowledge and insight. Teiresias may be blind but he sees and perceives more than Oedipus. Oedipus is a king well known for his quick wit and clear sight, he doesn’t see his true self. What’s worse is that his impairment isn’t limited to his personal history but also his deeper personality. He didn’t know who his real parents were but he also denied the his personal demons, anger, pride, arrogance… all of which chariots the ways towards forcing Teiresias to reveal his visions, obsession to control his faith that lead to his decision to run away, and him killing the man, who turned out to be his biological father, he argued with in his travel.
You mock my blindness, do you?
But I say that you, with both your eyes, are blind:
You can not see the wretchedness of your life… 
However, they share a common pain, that of helplessness. Teiresias knew that the path to his vision was laid out the moment Oedipus decided he wanted to know who his real parents were. Oedipus, on the other hand, knew he needed to stop it. Yet he didn’t know how to. No child would ever want to kill his father no marry his mother.
Oedipus decision to blind himself was the ultimate act of acceptance. Finally, after a lifetime of blindness, he sees. He knows his real identity, he knows the immensity of his crime, he knows the irony of the life he lived and the pain he caused. It was a dramatic justice but certainly not a moral redemption.
Oedipus admits guilt and takes full responsibility for his actions. Oedipus said:
Do not counsel me any more.
The punishment that I have laid upon myself is just.
If I had eyes I do not know how I could bear the sight of my father,
when I came to the house of death, or my mother:
for I have sinned against the both so vilely
that I could not make my peace by strangling my own life.”
The blind may not see form but it doesn’t mean they know less than those who see.