up to your eyeballs

(in) up to (one's) eye(ball)s

Extremely busy; deeply involved or engrossed (in or with something). I'd love to come for a pint, but I'm in up to my eyeballs with work for my class on Monday. John has been up to his eyes with the kids lately.
See also: up

up to (one's) eyeballs (in something)

Extremely busy (with something); deeply or overly involved (in something); possessing, filled up with, or overwhelmed by an excessive amount (of something). There's no way I can take a vacation right now, I'm up to my eyeballs in work at the moment! I only intended to be peripherally involved in David's business venture, but, before I knew it, I was in up to my eyeballs! Dana was worried she wouldn't find any work as an accountant working for herself, but she's up to her eyeballs in clients!
See also: eyeball, up
Farlex Dictionary of Idioms.

up to your eyeballs

If you are up to your eyeballs in an unpleasant situation, you are very deeply involved in it. He was out of a job and up to his eyeballs in debt. I simply won't have the time — I'm up to my eyeballs in work.
See also: eyeball, up
Collins COBUILD Idioms Dictionary, 3rd ed.
See also:
  • (in) up to (one's) eye(ball)s
  • eyeball
  • up to eyeballs
  • up to one’s eyeballs
  • up to your eyes
  • (in) up to (one's) elbows
  • a busy bee
  • busy bee
  • (as) busy as popcorn on a skillet
  • popcorn