Eye Infection

A hen around 6 or 7 years old has had eye issues for around two weeks. It began with her eye closed over with her eyelid, but has now developed to her eye open but it is cloudy/blue and her pupils is hidden. It seems that eye is blind. She is also lethargic. Ive never tried a topical ointment before, like a Terramycin ophthalmic ointment. Would an eye ointment be applicable, if not, how should I proceed. Thank you