Greetings!
I think your essay is off to a good start! You could make your thesis statement just a little more "explicit" like this: In Oedipus the King, Sophocles uses the blindness motif effectively by making Oedipus "blind" throughout the story by his refusal to see that the prophecy has come true, while Tiresias' physical blindness allows him to "see" the truth.
Your "famous quote" in your opening is not so famous that your reader will know who said it, so it really needs a citation, or at the very least, an attribution: As Samuel Butler said, "A blind man knows..." And you want to quote it correctly, too, so that it makes more sense. You might want to lead off with it:
Samuel Butler wrote "A blind man knows he cannot see, and is glad to be led, though it be by a dog; but he that is blind in his understanding, which is the worst blindness of all, believes he sees as the best, and scorns a guide." Blindness appears in all people, even if they possess the ability to "see." ... and so on. If you are using American English, put commas and periods inside the quotation marks.
Keep up the good work!
Thanks,
Sarah, EssayForum.com
Sarah, EssayForum.com