Hen with swollen eye

Good morning, noticed one of my hens has an eye swollen shut, no crust, no discharge, no bubbles... no other symptoms and she seems to be fine otherwise. Just wondering what I should do to remedy her eye and ensure she is not singled out by the other hens

Thanks for your suggestions

 

thanks for the reply...I've looked and cannot find anything in there, her eye seems fine

 

yes it is still swollen shut, i have her isolated from the others but I'm unsure of what to do for her... could it be eye worms?

 

should i treat with terramycin ointment and flush the eye with saline for a few days and see if anymore symptoms (respiratory) appear?