optical vs spottable

optical

adj
  • Of, or relating to sight; visual. 

  • Of, or relating to optics. 

  • Incorporating light-sensitive devices. 

  • Of, or relating to visible light. 

  • Designed to assist or enhance sight 

noun
  • Any special effect requiring laboratory work on the film. 

spottable

adj
  • Capable of being spotted (seen or noticed). 

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