Wiktionary
n. An artificial eye, not necessarily made from glass, intended to replace a missing eye.
WordNet
n. prosthesis consisting of an artificial eye made of glass
Wikipedia
Glass Eye were an influential art rock group based in Austin, Texas, and were primarily active from 1983 to 1993. Popular in Austin, and on the college radio and tour circuit, the band's unusual and unique musical style, blending melodic hooks with dissonance and occasional tendencies for the avant-garde, delighted critics. Considered "one of Austin's most popular and influential bands", their commercial success never matched their critical acclaim. Through self-release, and being signed to Wrestler and Bar/None Records, they released four LPs, two EPs and one single, and when the band regrouped in 2006, they released their previously lost final LP, Every Woman's Fantasy, on their own label, Glass Eye Records.
Usage examples of "glass eye".
And the shadows were pulled, I was pulled, toward that vast glass eye, that immense window behind which a shapeless Something stared to dine on gymnasium airs.
He figured that would tie in nicely with the glass eye which Basset still held in his hand.