Feather pecking

My hens are doing a lot of feather pecking. I have 10 and half are quite bald near the tail, these are both pecked and peckers! They have plenty of room in the run, it's approx 30 square m. They have outside perches, hanging things to play with and are fed on 16% protein layers pellets. Today I sprayed with anti-peck spray. This if anything seems to have increased the pecking! I don't see how to separate any out as most of them are doing it. Has anyone tried chicken goggles and if so how do they fit? Thanks for any help.

They're just coming to the end of a course of ivermectin as I thought they may have plumage mite, so that should have killed anything that thought it would make my hens their home! Having watched at least four of them pecking each other yesterday, funnily enough no pecking today! Maybe the anti peck spray is working?