leucoma vs walleye

leucoma

noun
  • An opaque area or scar on the cornea of an eye 

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 leucoma and walleye occurred in a corpus of books? (source: Google Ngram Viewer )