glasses vs pair of specs

glasses

noun
  • Spectacles, frames bearing two lenses worn in front of the eyes. 

  • Field glasses; binoculars. 

pair of specs

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. 

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