up to one's eyeballs vs up to one's eyes

up to one's eyeballs

phrase
  • Deeply engaged in something, to the point of being overwhelmed. 

up to one's eyes

prep
  • Synonym of up to one's eyeballs 

How often have the words up to one's eyeballs and up to one's eyes occurred in a corpus of books? (source: Google Ngram Viewer )