DON’T CROSS YOUR EYES … THEY’LL GET STUCK THAT WAY! Copyright © 2011 by Dr. Aaron Carroll and Dr. Rachel C. Vreeman. All rights reserved. For information, address St. Martin’s Press, 175 Fifth Avenue, New York, N.Y. 10010.

www.stmartins.com

ISBN 978-0-312-68187-6

First Edition: July 2011

eISBN 978-1-4299-6995-6

First St. Martin’s Griffin eBook Edition: July 2011