okulvitro

Etymology
Compound of. Compare 🇨🇬.

Noun

 * 1) eyeglasses, spectacles, pair of glasses
 * 2)  a lens of a pair of eyeglasses
 * 3) monocle
 * 1) monocle
 * 1) monocle

Usage notes
The first Esperanto dictionary, the 1894 Universala Vortaro, used plural for eyeglasses. The vicissitudes of usage have given the singular an identical meaning.