The imformation on this page is borrowed from wikipedia.com.

"In Greek mythology, Tiresias (also transliterated as Teiresias) was a blind prophet, the son of the shepherd Everes and the nymph Chariclo.

Tiresias' daughter Manto was also gifted with prophecy.

Tiresias was a priest of Zeus, and as a young man he encountered two snakes mating and hit one of them with his staff, the female one. He was then transformed into a woman. As a woman, Tiresias became a priestess of Hera, married and had children, including Manto. According to some versions of the tale, Lady Tiresias was a prostitute of great renown. After seven years as a woman, Tiresias again found mating snakes, he made sure to strike the male with his staff this time and became a man once more. As a result of his experiences, Zeus and Hera asked him to settle the question of which sex, male or female, experienced more pleasure during intercourse. Zeus claimed it was women; Hera claimed it was men. Tiresias sided with Zeus, saying that on a scale of one to ten, women enjoy sex nine to men's one. In a rage, Hera struck him blind. Since Zeus could not undo what she had done, he gave him the gift Inner sight. An alternative story in Callimachus' poem "The Bathing of Pallas" has it that Tiresias was blinded by Athena after he stumbled onto her bathing naked. His mother, Chariclo, begged her to undo her curse, but Athena couldn't; she took the serpent from her aegis and commanded it to lick his ears, giving him prophecy instead.

Stripped of its narrative and anecdotal and causal connections, the mythic figure of Tireisias combines several archaic elements: the blind seer; the impious interruption of a natural rite (whether of a bathing goddess or coupling serpents); serpents and staff (Caduceus); a holy man's double gender (shaman); and competition between deities.

Tiresias's background was important, both for his prophecy and his experiences. Greek mythology contained many hermaphroditic figures (including Hermaphroditus), but Tiresias was fully male and then fully female. Also, prophecy was a gift given only to the priests and priestesses. Therefore, Tiresias offered Zeus and Hera evidence and gained the gift of male and female priestly prophecy.

In Oedipus the King, by Sophocles, Oedipus calls upon Tiresias to aid in the investigation of the killing of Laius. Tiresias refuses to give a direct answer and instead hints that the killer is someone Oedipus really does not wish to find. After Oedipus blinds himself and wanders, Tiresias appears in Antigone, also by Sophocles.

Tiresias died after drinking the water from the spring Tilphussa, where he was struck by an arrow of Apollo. After his death he was visited in the underworld by Odysseus, to whom he gave valuable advice concerning the rest of his voyage, specifically concerning the cattle of Helios, which Odysseus' men did not follow."