spectacles vs viewfinder

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”) 

viewfinder

noun
  • A device on a camera that shows what will appear in the field of view of the lens; it helps the user target a subject, zoom and focus the image. 

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