Monday, December 13, 2010

History-ocular prosthesis or artificial eye

The earliest known evidence of the use of ocular prosthesis is that of a woman found in Shahr-I Sokhta, Iran [1] dating back to 2900–2800 BCE.[2] It has a hemispherical form and a diameter of just over 2.5 cm (1 inch). It consists of very light material, probably bitumen paste. The surface of the artificial eye is covered with a thin layer of gold, engraved with a central circle (representing the iris) and gold lines patterned like sun rays. On both sides of the eye are drilled tiny holes, through which a golden thread could hold the eyeball in place. Since microscopic research has shown that the eye socket showed clear imprints of the golden thread, the eyeball must have been worn during her lifetime. In addition to this, an early Hebrew text references a woman who wore an artificial eye made of gold (Yer. Ned. 41c; comp. Yer. Sanh. 13c). Roman and Egyptian priests are known to have produced artificial eyes as early as the fifth century BCE constructed from painted clay attached to cloth and worn outside the socket.[3]

The first in-socket artificial eyes were made of gold with colored enamel, later evolving into the use of glass (thus the name "glass eye") by the Venetians in the later part of the sixteenth century. These were crude, uncomfortable, and fragile and the production methodology remained known only to Venetians until the end of the 18th century, when Parisians took over as the center for artificial eye-making. But the center shifted again, this time to Germany because of their superior glass blowing techniques. Shortly following the introduction of the art of glass eye-making to the United States, German goods became unavailable because of WWII. As a result, the US instead made artificial eyes from acrylic plastic.[3]

Modern ocular prosthetics has expanded from simply using glass into many different types of materials


Limits of realism
Ocularists and eye surgeons have always worked together to make the most realistic artificial eye. For decades, all efforts and investments to improve the appearance of artificial eye are neutralized by the immobility of the pupil. A solution to this problem has been demonstrated recently.[4] The device is based on a LCD which simulates the pupil size as a function of the ambiant light.




3rd Millennium BC Artificial Eyeball Discovered in Burnt City

Skeleton of a woman having an artificial eye unearthed in Burnt City, southeast Iran
Discovery of an artificial eyeball belonging to 4800 years ago in the historic site of Burnt City has astounded archeologists.
Tehran, 10 December 2006 (CHN Foreign Desk) -- Archeologists in Burnt City announced unprecedented discovery of an artificial eyeball, dated to 4800 years ago, in this historic site.
 
Announcing this news, director of Burnt City archeology excavation team, Mansour Sajadi, said that this eyeball belongs to a sturdy woman who was between 25 to 30 years of age at the time of death. Skeletal remains of the woman were found in grave number 6705 of Burnt City’s cemetery.
 
Regarding the material used to make this artificial eyeball, Sajadi said: “The material this artificial eyeball is made of has not yet been determined and will be assessed through later testing. However, at first glance it seems natural tar mixed with animal fat has been used in making it.”
 
Initial studies on the eyeball also suggest formation of an abscess in the eyelid due to long-term contact with the eyeball. Moreover, remaining eyelid tissues are still evident on this artificial eyeball.
 
According to Sajadi, even the most delicate eye capillaries were drawn on this eyeball using golden wires with a thickness measuring less than half a millimeter. There are also some parallel lines around the pupil forming a diamond shape. Two holes are also seen on the sides of this eyeball to hold it in the eye socket.
 
Initial anthropological studies on the remaining skeleton of the woman to which this artificial eyeball belong revealed that she was of mixed race and died 4800 years ago between the ages of 25 to 30.
 
A number of clay vessels, ornamental beads, a leather sack, and a bronze mirror have also been found in the grave of this woman.
 
Located 57 kilometers from the city of Zabol in Sistan va Baluchistan province, southeast Iran, Burnt City is one of the most important prehistoric sites of the country which was well developed during the third millennium BC.
 
Spreading over a 300,000 hectare area, Burnt City was recently recognized as mainland-Iran’s largest prehistoric site. The city experienced four stages of civilization and was burnt down three times, which is why it was named ‘Burnt City.’ Discovery of hundreds of historical sites including 166 satellite villages together with large numbers of archeological relics, skeletons, and ancient structures in the archeological site of Burnt City makes it holder of an unparalleled record in the history of archeological activities in Iran.
 
 
Maryam Tabeshian
foreigndesk@chn.ir
for more information
http://www.chnpress.com/news/?Section=2&id=6857

2 .  

5,000-Year-Old Artificial Eye Found on Iran-Afghan Border

 

  






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