I had the same thing happen to two of my birds when it started to get colder. Swollen eyes with a bit of bubbles. I took one to the vet but didn't have any of the testing done. Pointless, I know. The vet gave me some Tylan powder to put in their water, though. I started with the recommended dose of Tylan but after no improvement in 2 weeks (two VERY frustrating weeks), I doubled the dose. It was gone in a week after that. Three weeks is a long time to keep two bored chickens in a bathtub. Hopefully you'll be able to clear it up faster than I did.
Good luck!