1eye·ball 
/ˈaɪˌbɑ:l/ noun
plural eye·balls /ˈaɪˌbɑ:l/ noun [count] : the entire round part of the eye
up to your eyeballs
informal : deeply involved in something
▪ We're up to our eyeballs in work. [=we are very busy]
▪ We're up to our eyeballs in work. [=we are very busy]
