optical glass

Etymology
from being the type of glass used for optics

Noun

 * 1) A class of glass used to create optical lenses, such as that for spectacles or spyglasses

Hyponyms

 * "glass" (not plastic) lens glass for eyeglasses
 * "glass" (not plastic) lens glass for eyeglasses
 * "glass" (not plastic) lens glass for eyeglasses