Is there something wrong with my chicken?

[gtourtel]

I have a Black Astrolorp named Gertrude she is blind in one eye from and attack. We have had her for almost a year she is about 2-1/2 years old. For the past 3 or 4 days she has not been out of the coop (we free range). She is always on the perch when I go into the coop and she holds her tail feathers up other wise she seems fine. Not sure what to look for. Please help!