Kitten with Discharge From One Eye?

She's a small stray kitten, and its mother feeds them bugs and mice, (and all in my backyard, ewww poor things). Well they are covered in dirt and fleas and are underfed. I heard original dish dawn Blue paralyzes the fleas. But one of the kittens eyes is swollen, and its oozing mucus, and it is so sad and disgusting and I used warm water, but the eye was swollen and checked and the eye is crusted over again. I don't have the money for anything expensive, and they are too young to take to a shelter so I want to help them... Please!