One of our one year old red sex-links has had swelling under her eye and now it is to the point when she cannot see out of one eye. We have been fighting this issue since mid-winter and it improved somewhat with 7-10 days of a once a day dose of 1/2 ML of Tylan but it does not seem top be improving. She is eating fine, active, and is producing eggs and there is no fluid leaking from her eyes. I have searched the internet to no avail. Can anyone provide any further recommendations to help us to heal her? I have attached two photos so you can see the good eye versus the swollen eye. Many thanks for your advice! It's our first year with backyard hens so this is all new to us.