One-Eyed Anomaly Photograph courtesy Marcela Bejarano-Álvarez Talk about a one-of-a-kind discovery—an extremely rare cyclops shark (pictured) has been confirmed in Mexico, new research shows. The 22-inch-long (56-centimeter-long) fetus has a single, functioning eye at the front of its head—the hallmark of a congenital condition called cyclopia, which occurs in several animal sp