I noticed a few days ago one of my silkie hens standing off by herself. The top front part of her head was swollen and she was extremely thin. I isolated her thinking it was an infection from an injury. However, now I'm thinking it might be something worse. She acted like she could not see, so I shined a light in her eyes the pupil didn't constrict. I cannot find any injury to her head at all. There is no nasal or eye discharge. The hen is from a 2007 hatch so she is 4-5 years old. She is listless and can't keep her balance. However, she is very thin and since she can't see I doubt she was eating/drinking which made her weak. I put food and water in front on her and got her to eat a little and drink some. I'll be surprised if she makes it until the morning. Although I did get her to drink she has a dehydrated odor to her - I know that seems weird but that is the best way I can describe it. Any clue what could of caused this swelling and blindness? The first pic is of the front of her face; the second pic is after I cut back some of the feathers to try to find out if she was injuried. BTW she does not have a vaulted skull - that is all swelling.