How can the reader analyze a line in which Oedipus describes the "reversal" (change in fortune) that happened to him in Oedipus Rex?
There are a number of points in Oedipus Rex in which the fortune of the King of Thebes begins to change, such as when Oedipus sends Creon to seek the oracle of Apollo, when Teiresias arrives, and when the shepherd is brought before Oedipus. But, certainly, in the mind of Oedipus the true reversal of fortune comes with his realization that his life has all been an illusion and a disgrace. Whereas he has believed himself a noble man deserving of the honors bestowed upon him as the one who has been able to solve the riddle of the Sphinx, as King of Thebes, Oedipus, in reality, lives a life that he learns is a pollution.
Ah! Ah! How miserable is my life!
Where does my pain take me?
How does my voice rush about me?(1340)
O doom, how you’ve pounced!
In line 1341, Oedipus expresses his comprehension of this pollution that is his life. Having demanded that the seer Teiresias speak and explain what has caused the plague upon Thebes, and having demanded that the shepherd who found him as a child be brought before him, Oedipus learns the truth about himself. Rather than being a noble king, Oedipus has brought tragedy upon his mother/wife Jocasta and shame upon his children/siblings. In such a short time, doom has come to him in the greatest of misfortunes, the realization that his life has been a lie and he is guilty of incest.