magnifying glass vs spectacles

magnifying glass

noun
  • An instrument made of convex glass, used to magnify. 

spectacles

noun
  • A pair of lenses set in a frame worn on the nose and ears in order to correct deficiencies in eyesight or to ornament the face. 

  • Synonym of pair (“score of zero runs in both innings”) 

How often have the words magnifying glass and spectacles occurred in a corpus of books? (source: Google Ngram Viewer )