You mention that she is blind in one eye and her other eye looks odd and she is underweight. All these things could be due to Marek's disease. Was she vaccinated for it. Tumours are a symptom of Marek's too. I'm not saying this is a tumour because the photos are too blurry to see much and there is little you can do if it is Marek's. A photo of her good eye that looks odd might help. Marek's is caused by a virus and symptomatic birds are actively shedding the virus via dander dust, which is them inhaled by other hens to infect them, so you may want to consider taking precautions to reduce the risk of it spreading in case it is Marek's although the chances are your other birds have already been exposed.
If you could get some clearer photos of the problem, more people might be able to help.
