I say that you are Laius' murderer - He whom you seek.
Not without chastisement shall you, twice over, utter wounds!
I thought I heard you say Laius was slain where three roads meet!
What stress of trouble is on you, that you say so?
Woe! woe! It is all plain, indeed! O Light, this be the last time I shall gaze on thee.
For if thou art the man he says, sure thou wast born destined to misery!
Oedipus' great error in judgment was killing Laius, as a result of his hubris. As Tiresias states that Oedipus the killer of Laius, Oedipus' hubris is present in this scene as well as he refuses to believe Tiresias.
The initial "reversal of fortune" occurs when Jocasta recounts the prophecy and circumstances of Laius' death. The location of Laius' murder sounds familiar to Oedipus. He suddenly wonders if the prophecy could have actually become true.
Oh, Oedipus... It had to be done.
After Oedipus pieced together most of the clues regarding his parentage, Oedipus just needed for the old man to confirm that the baby he gave to the messenger was, in fact, Laius and Jocasta's baby. Once it is confirmed, Oedipus experiences shock and anguish as he learns he married his mother and killed his father.
Although the point of Catharsis in Oedipus Rex is debatable, the point where Oedipus pierces his eyes with Jocasta's golden brooches is the most dramatic and violent moment of Catharsis. Here, Oedipus is finally taking control of his own fate and blinding himself in order to not have to witness the evils manifest in his life as a result of the prophecy.
I know not how with seeing eyes I could have looked upon my father - coming to the under-world, or my poor mother, when against both I have sinned sins, worse than a halter's meed.
Hermes, Apollo, Artemis, Zeus, and Athena all looking down on Oedipus, feeling pity for his horrible fate.