unseen vs unsighted

unseen

adj
  • Not seen or discovered; invisible. 

  • Unskilled; inexperienced. 

  • Not hitherto noticed; unobserved. 

noun
  • An examination involving material not previously seen or studied. 

unsighted

adj
  • Not sighted; unseen. 

  • Not furnished with a sight. 

  • Without the sense of sight; blind. 

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