In Oedipus Rex the characters are deceived by their relationships. In the case of the relationship between Oedipus and his mother/wife, Oedipus unknowingly married his mother. Because of a prophecy that has been made it causes Oedipus to take a step back and examine his life. Through examining he finds his wife to be his mother. This realization causes him to gouge out his eyes and exile himself. The relationship with his mother/wife turned out to be harmful because he grew up believing that someone else was his mother and father. The lack of information that he had about his life caused him to destroy his relationships.
His relationship with his father was also destroyed. Because Oedipus did not know who his real father was, he killed him. Oedipus never got to have a relationship with his father. Without the guidance of his real father, Oedipus loses some direction in his life.
Oedipus is also transformed by his relationship with Tiresias. Tiresias accuses Oedipus of killing his father and marrying his mother. Oedipus gets defensive and angry when he hears those words. Because of his ignorance Oedipus is unable to accept the truth from Tiresias and causes him to question those around him.
Oedipus is missing something from the relationships he has with people. He does not truly know who the people are. The lack of information causes conflict and pain that can not be undone.