spectacle :
Idioms & Phrases
Idioms/Phrases
Prefix/Suffix
Associated
Related
Dictionary
Index
Periscopic spectacles
Periscopic spectacles
(Opt.)
, spectacles having concavo-convex or convexo-concave lenses with a considerable curvature corresponding to that of the eye, to increase the distinctness of objects viewed obliquely.
Webster 1913