The Graeae were the sisters who shared one eye and one tooth in Greek mythology.
The Graeae—usually named Deino, Enyo, and Pemphredo—were ancient sisters connected with the sea gods Phorcys and Ceto. Their unusual shared possessions became an important obstacle in the story of Perseus. By taking the single eye while the sisters passed it between them, Perseus forced them to reveal information needed for his quest.
They are not the same beings as the Gorgons. The Graeae were described as gray-haired from birth and associated with old age, while the Gorgons were monstrous sisters including Medusa. The two groups appear together in many retellings because both belong to the supernatural family surrounding Perseus’s adventure.
The shared eye is one of the most memorable details in the myth, but ancient accounts differ in the exact names and number of the Graeae.