pair of eyeglasses vs specs

pair of eyeglasses

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. 

specs

noun
  • Specifications: plural of spec 

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