birth control glasses
n.pl.— «Right now they’re both wearing Army-issue brown heavy plastic frames, which the soldiers call BCGs, birth control glasses, because they’re so ugly no woman would want to make a baby with a soldier wearing a pair.» —“Dynamic duo in combat zone/Identical twin brothers share bond and serve together” by Frank Bruni Houston Chronicle (Texas) Feb. 24, 1991. (source: Double-Tongued Dictionary)