Comment on Sophocles' use of dramatic irony in Oedipus?

One example of of Sophocles use of dramatic irony comes when the old soothsayer visits the King. Oedipus ridicules the man because he's blind, and Tiresias in a fit of anger tells the king that though he can see he is "blind" to the truth. When Oedipus becomes blind, he finally realizes the truth of the man's words. Irony is also to be found in the fact that it is the blind man who truly sees.

In the play, there aer two different attempts to avert the working of fate. When an oracle tells the king Laios that his son will kill him and marry his own mother, Laios and Jocasta give their infant son to a servant to leave him on a hill said to be killed there; and when Oedipus hears the same prediction, he leaves Corinth to avoid the shameful situation. In both cases, Fate completed it's dreadful course of action and foiled the attempts of Laios, Jocasta and oedipus.