"glass lenses to help a person's sight," early 15c., from plural of spectacle.
mid-14c., "specially prepared or arranged display," from Old French spectacle, from Latin spectaculum "a show, spectacle," from spectare "to view, watch," frequentative form of specere "to look at," from PIE *spek- "to observe" (see scope (n.1)).
spectacles spec·ta·cles (spěk'tə-kəlz)
n.
See glass.