Chicken with bubbles on eye

[Jose11632]

One of my brahmas has some bubbles in the corner of her eye at times she doesn’t and sometime she does only on one eye her nostrils are dry their hasn’t been a change in weather, she acts completely normal. No coughs or sneezes. Got Tylan 50 at hand. Also 4 weeks ago she sneezed or coughed(don’t really know the difference between them) when eating her layer crumble, when ever she ate it, now they eat layer pellets and that’s taken care of. What could it be?

 

[Jose11632]

The weather hasn’t gotten different, no vermin or birds can make contact with her. Got ventilations from the left and right and front side where the wind flows at times

 

[Jose11632]

It barely happened today her eye was good in the morning she was taking a dirt bath and when done she was shaking her head and scratching her head like something got in her eye. Also have noticed when hens fight and one gets hurt in the eye they get bubbles or when something like green yogurt falls in their eye bubbles form as well