I believe you will be OK you just need to let your bosses know you have epilepsy. I'm sure you will be fine

As a working person with epilepsy myself, that takes at least 6 cruises a year. I say go for it. Don't let epilepsy keep you from doing anything you want to do. Also when you do go back. Don't be afraid to let your close coworkers know about your epilepsy. That way you will have an onboard team. I can honestly say that I have never let epilepsy keep me from doing anything I really wanted to do. You shouldn't be any different.

I would say because the cruise ship has an image to protect. The cruise ship would not want any of their staff to show they have seizures.