Another member posted a question concerning the very swollen eye of one of their chickens; it led to a super useful discussion of the various respiratory ailments that can afflict chickens, including those that cause symptoms such as bubbly eyes. I followed it because I, like you, had two chickens with bubbly eyes (and one chicken with extremely labored, rattling breathing). The link to the thread is here:
https://www.backyardchickens.com/forum/viewtopic.php?id=36823&p=1
It is most likely: Infectious Bronchitis, Infectious Coryza, or Infectious LT (short for a long scientific name). Although not apparently transferable to humans or other pets, these diseases are potentially very contagious to other chickens; once you know what you have, I suggest you vaccinate your healthy chickens ASAP. There is a lot of useful information in the thread, I encourage you to look at it. Especially useful, on either page 3 or 4, is a post from a chicken vet which runs through a series of potential treatments. I had already tried Terramycin, Tylosin and injectable Tylan 50 with little to no result. After reading the thread, I went to First State Vet supply (
http://www.firststatevetsupply.com/store/index.php) and purchased Sulmet powder (a powerful Sulfa antibiotic added to their drinking water) and Ciloxan eye drops. I also purchased a vaccine for ILT, which is administered as an eye drop (it requires two applications; the second follows the first by 6 weeks)-I did this to hopefully protect my healthy chickens from getting sick; I am also considering vaccinating them for IC and IB (also available at First State Vet Supply). I have seen dramatic improvement in the chicken whose eyes were least bubbly; the other is still struggling but, like your chicken, all three of my little sickies are active and eating. I suggest that you check out the thread and consider contacting the people at First State to see if they have any input. I did so, and will pass on any information I get from them.
Good luck! There are a lot of useful treatments out there, so stay calm
