I have a chicken with one eye that wont stay open, it is fine apart from that eating drinking laying eggs. It has no discard from eyes or nostrils but the eye seems to be getting more swollen from her scratching at it.
Would it help to try pink eye spray?
I would recommend taking the chicken to a veterinarian. The swollen eye may not be caused by an infection it could be due to an injury or even an eye worm and in any case a vet should be consulted to prescribe the right course of treatment.