I haven't seen anything quite like it - it does look to be the eyeball or a covering over it. I would try washing with saline solution.
By the way, when I was at my vet's buying the anitbiotic eye ointment for one of my chickens, she said "You know, you can use Neosporin - it works just as well." I bought the eye ointment but filed away her advice for future use.