look around vs look in on

look around

verb
  • To take note of what is going on; to make oneself aware. 

  • Used other than figuratively or idiomatically: see look, around. 

  • To turn one's head to see what is behind oneself. 

  • To inspect a building or area. 

  • To search a place. 

look in on

verb
  • To check that (someone or something) is okay or that a process is continuing appropriately; to check up on; to monitor (someone) through brief, often surreptitious checks. 

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