Chicken has white mass in eye... what to do?

[Rooapalooza]

Yesterday morning I noticed my chicken had her eye closed. There was white in it like there is now which grew very quickly throughout the day. I ran to the store and got colloidal silver and vetrx which I have been applying to her head and eye alternately. It actually looks a tiny bit better today. The hen has been behaving normally, but by normal I mean sitting in the shade all day because it's been over 100°f with at least 60% humidity all week. My question is what should I be doing about this? What is it? Should I try to pull out the white sac? Should I just keep applying the medicine?

In the first picture she is blinking. As far as I can tell it showed up yesterday morning. Thanks in advance!

 

[Rooapalooza]

Also none of my other chickens have it and her other eye looks fine. I put her in a pen yesterday but she escaped and was free ranging with the flock when I got home with her meds. Clever girl. I'm not sure if I need to separate her again.