up to (one's) eyes (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 eyes in work at the moment! I only meant to be peripherally involved in David's business venture, but, before I knew it, I was in up to my eyes! Dana was worried she wouldn't find any work as an accountant working for herself, but she's up to her eyes in clients!
up to your eyes
If you are up to your eyes in work or in an unpleasant situation, you are very busy with it or are deeply involved in it. I'm afraid I'll be late getting back. I'm up to my eyes in work. He's up to his eyes preparing for the trip. By this time Walker was up to his eyes in debt.
up to your eyes in
very busy with or deeply involved in. informal