vision vs will o' the wisp

vision

noun
  • An ideal or a goal toward which one aspires. 

  • Something unreal or imaginary; a creation of fancy. 

  • Pre-recorded film or tape; footage. 

  • Something seen; an object perceived visually. 

  • Something imaginary one thinks one sees. 

  • The sense or ability of sight. 

  • A religious or mystical experience of a supernatural appearance. 

  • A person or thing of extraordinary beauty. 

verb
  • To imagine something as if it were to be true. 

  • To present as in a vision. 

  • To provide with a vision. 

will o' the wisp

noun
  • A delusionary or otherwise unachievable goal that one feels compelled to pursue. 

  • A flickering light or lantern, especially over bogs, swamps or marshes, held by a supernatural creature who uses it to lure travelers at night to their demise. 

How often have the words vision and will o' the wisp occurred in a corpus of books? (source: Google Ngram Viewer )