follow up to eye drops

[BCbirder]

I was grateful to get help getting eye drops thanks to posting here on this message board. It was for an older auracauna hen. She had the drops in July and got weepy eyes again in Oct when the weather changed. I ordered more drops and the eye cleared up again.

After a few days both eyes got watery again. I gave her drops again but is there a chance that I can overdo it?
Should I be getting another type of drop? I got them from Dr Peter Brown.

 

[BCbirder]

I still have this hen that has an eye infection. I gave those eye drops and soon the infection came back and now it seems to stay. She eats even though her vision is affected by the swelling on her left side.
Does anyone have any ideas or experience with an eye infection that has lasted this long (over 2 years)? I got her as an adult and all the others (7) that came with her died, most within the first month. She is still going strong. She gets better in the summer, starts to lay eggs and then her eye flares up and she tops laying. I would like to do something to help her get better.