Tiresias is the iconic blind seer. This guy may not be able to see the hand in front of his face, but he can see pretty much everything that's going to happen. Though he's super old and has been trying to advise the kings of Thebes for years, they never seem to listen to his advice, which we're guessing is the very thing that makes him so cranky all the time. In the story of Oedipus, he at first refuses to tell Oedipus the truth of everything, because he knows no good will come of it. In the end, though, Oedipus is all mean to him and Tiresias spills the beans.
For the full story on the blind seer of Thebes click here. To see how he butts heads with Creon in Sophocles' Antigone click here.