I need some help with coming up with thesis statement for Oedipus Rex; it is a formal essay.

This is a
broad request, because you can say many things about ' play, .  Since you
need a thesis statement, let me suggest a few of them. 

First, one thesis
statement could be: Even thoughwas fated to kill his father and marry his mother, he brought
about his own downfall by his own . 

If this is your thesis, you have a lot
of material with which to work. You can point to his arrogance and pride. For example, the
oracle of Delphi had three key maxims: (1) nothing in excess (2) know thyself (3) make a pledge
and destruction is near. Oedipus broke every one of these. From this point of view, he brought
about his own downfall. 

Here is another thesis. Physical blindness leads to
sight. 

This is a short thesis, but there is also a lot of material with
which to work. You can bring up , the blind seer. Even though he is blind, he sees. On the other
hand, Oedipus can physically see, but he is blind to who he is and what he has done. Later in
the play, he blinds himself. When he does this, he really sees.