How Was Oedipus Moraly Blind In "Oedipus The King"?

When Oedipus is born it is prophesied that he will kill his father and marry his mother. His parents try to have him killed to prevent this; but the only result is that when he meets his parents as an adult, he doesn't recognise them or they him; which is how he ends up killing his father (over a dispute over the right of way, when they meet in the road) and later marrying his mother. This is an example of his moral blindness; he doesn't know who he is or his place in the world. The idea is underlined by the fact that he gains his kingdom of Thebes by killing a much older man in anger (even though he doesn't know Laius is his father) and taking over his property, including his wife.

THe "blindness" of ignorance in which Oedipus has lived his life is given dramatic expression when, much later, he finds out the truth and physically blinds himself.