Many ducks are currently molting this time of year (mine included). The duck feathers all over and missing feathers on various parts of the body is usually a good indicator. The eye more than likely is from a different issue entirely. If her eye continues to bother her and a vet is not an option, Terramycin is an antibiotic ointment for eyes that is safe for poultry. I don't know what stores carry it in person, but I buy mine from:
https://www.chewy.com/terramycin-op...lHnwLOYODYedBtarBhBqF8rpIALGSEyBoCvZUQAvD_BwE