An ocular prosthesis or artificial eye (a type of Craniofacial prosthesis) replaces an absent natural eye following an Enucleation, evisceration, or orbital exenteration. The prosthetic eye fits over an orbital implant and under the eyelids. Typically known as a glass eye, the ocular prosthesis roughly takes the shape of a convex shell and is made of medical grade plastic acrylic. A few ocular prosthetics today are made of cryolite glass. A variant of the ocular prosthesis is a very thin hard shell known as a scleral shell which can be worn over a damaged eye. Makers of ocular prosthetics are known as ocularists. An ocular prosthetic does not provide vision; this would be a visual prosthetic. Someone with an ocular prosthetic is totally blind on the affected side and has monocular (one sided) vision which affects depth perception.
The earliest known evidence of the use of ocular prosthesis is that of a woman found in Shahr-I Sokhta, Iran dating back to 2900-2800 BCE. 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.
The first in-socket artificial eyes were made of gold with colored enamel, later evolving into the use of glass 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 Paris took over as the center for artificial eye-making. But again shifted to Germany with 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.
Currently, modern ocular prosthetics has expanded from simply using glass into many different types of materials.
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