If pus is not removed they can lose the eye or be blinded. Here is some reading about similar eye problems, and how to get pus out with pictures:
https://www.backyardchickens.com/threads/nasty-eye-infection-pics.1071718/
https://www.backyardchickens.com/th...e-sinus-lump-swelling-cure-treatment.1156995/
https://www.backyardchickens.com/threads/nasty-eye-infection-pics.1071718/
https://www.backyardchickens.com/th...e-sinus-lump-swelling-cure-treatment.1156995/