What do you call a prosthesis used to replace an eye?

The term used to refer to a prosthesis that replaces an eye is "artificial eye." This term broadly encompasses devices designed to mimic the appearance of a natural eye. An artificial eye is typically used when an eye has been lost due to injury, disease, or congenital conditions, and it serves both a functional and aesthetic purpose.

While "glass eye" is another term that is often used colloquially, it specifically refers to an older type of artificial eye made from glass. In contemporary medical terminology, "artificial eye" is preferred as it can refer to more modern materials and designs that may not be glass. Contact lenses and vision implants serve entirely different purposes—contact lenses are typically used to correct vision rather than to replace an eye, and vision implants are surgical devices used to improve sight rather than replace the eye itself. Thus, "artificial eye" is the most accurate and widely accepted term for an eye prosthesis.