Assertion: plastic lens | /r/Synonym | mineral glass
Facets:
value: sometimes
type: TEMPORAL
Source sentences:
text: During the 20th century, cheap, lightweight, reliably made plastics became widely available and most low-cost optical devices now use plastic lenses (sometimes known as "organic glass"—made from materials such as polycarbonate) in place of glass ones (sometimes known as "mineral glass" to differentiate it from plastic equivalents).