"Little One-Eye, Two-Eyes, and Three-Eyes" is a German fairy tale collected by the Brothers Grimm, tale number 130.
A woman had three daughters: The eldest had one eye in the middle of her forehead, the second had two eyes like ordinary people, the third had three eyes; two on the sides of her head and a third in the middle of her forehead. Her mother and sisters scorned Little Two Eyes because she was like other people and treated her badly, leaving her only their leftovers to eat...