strabismus vs walleye

strabismus

noun
  • A defect of vision in which one eye cannot focus with the other on an object because of imbalance of the eye muscles; a squint. 

walleye

noun
  • One or a pair of sideways-looking misaligned eyes. 

  • An unusually pale eye. 

  • A species of gamefish, Sander vitreus, native to the Northern U.S. and Canada with pale, reflective eyes. 

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