How have you been treating them? Can you post some more photos, especi
ally of the one you are going to have to cull?
Looking at your other threads, it looks like you may be dealing with Fowl Pox, which if it's the dry form, will usually resolve itself in several weeks. If there is pus in the eyes or lesions inside the beak/throat or they have respiratory symptoms then you may have Wet Form Fowl Pox or possibly a respiratory illness with complications. To help with eye infection you can apply an ophthalmic ointment like Terramycin or similar.
After Fowl Pox has run it's course, chickens build a resistance. It can be spread through shared water and sloughing off the scabs, but is commonly spread by mosquitoes. There are vaccines available if you live in an area that has a lot of mosquitoes.
Keep your water stations cleaned and sanitized - good information and instructions are found here:
http://www.the-chicken-chick.com/2015/07/fowl-pox-prevention-treatment.html
If you have vet care, that is always best.
This particular pullet you posted a photo of - it could be Fowl Pox, but the scab almost looks like injury. You may want to watch to see if they are pecking at one another and cover any sharp edges in their housing with tape to eliminate getting cut.
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View attachment 1189127
https://www.backyardchickens.com/threads/what-is-wrong-with-my-chicks-eye.1207649/
https://www.backyardchickens.com/threads/what-is-this-in-my-pullet-beak-eye-and-comb.1204489/