Dogon

A Dogon Sixth Eye was one of the eyes of a Dogon, known for its special powers. Using it, a person could look back at their life more clearly. When ingested, Eugene Jones retained a presence in the world after dying. His ghost was able to influence the mind of Gwen Cooper and eventually became corporeal in order to save her life, whereupon he floated away into the afterlife. (TW: Random Shoes)

History
The Sixth Eye was first found on Earth after the Dogon arrived around the Great Fire of London. (WEB: torchwood.org.uk)

In the 1980s, Mr Garret watched a Dogon Sixth Eye fall from the sky while golfing, landing in the sand trap he was stuck in. In 1992, he gave it to Eugene Jones as a consolation prize for a maths competition that his team had lost due to Eugene's nervousness. (TW: Random Shoes)


 * Though unstated, it is likely that the eye came to Earth via the Rift.

After the Battle of Canary Wharf, Dogon Sixth Eyes appeared on eBay and became very popular in Belgium. (WEB: torchwood.org.uk)

In 2007, Eugene decided to sell his Dogon eye on eBay. His friends Gary and Josh bid up the price to cheer him up. However, they accidentally won. They planned to buy the eye and resell it at a greater price. When they tried to take the eye by force, Eugene swallowed it and ran away. Though he was later killed, the eye brought him back as a ghost-like being, allowing him to help Gwen Cooper investigate his death. He remained halfway between life and death even when the eye was removed from him. Torchwood Three retrieved the eye. (TW: Random Shoes)

The collector Henry Parker also had a Dogon eye. (TW: A Day in the Death)