It's possible she may have gotten debris in the eye. Flush it with saline solution, then apply a small dab of antibiotic ointment in her eye. Here, we use Terramycin eye ointment, or over the counter ointments such as Neosporin or Triple Antibiotic ointment. Use as needed.
I also recommend trimming the feathers and fluff around her eye. It's possible fluff or feather might be irritating her eye. I've had to trim fluff from Easter Eggers due to eye irritation.
Have you noticed any head shaking, eye scratching, turning her head and wiping her eye on the right side of her body? If so, it could be eyeworms. However you'll be able to see them in her eye. They are white in color and about 1/8th inch long.
If there are other symptoms such as sneezing, wheezing, head shaking, facial swelling, runny nostrils...it could be the onset of a respiratory disease.
I'm covering all the possibilities but I suspect it might be debris in her eye or a feather irritating her eye.