Dec. 18, 2006 — Around the time that the great pyramids were built in Egypt and Stonehenge was erected in England, a young woman living in what is now Iran lost an eye and was fitted with a prosthetic device.

"At first glance, it seems natural tar mixed with animal fat has been used in making [the eye]," said archaeologist Mansur Sayyed-Sajadi, who is directing the excavation. Further testing will be needed to determine its exact composition.

The eyeball was found with the skeletal remains of its wearer in an early cemetery. The researchers believe the woman was between 25 and 30 years old when she died.