Strange bump under roosters eyelid

[Smelly]

My bantam Cochin rooster has had a strange bump under his eyelid for a while, it’s not really seemed to get any bigger but it’s not gone away at all, does anybody know what this could be, whether it’s dangerous or not and if there’s a way to treat it?

 

[Eggcessive]

I have seen a hard cyst in one of my cockerels in the same location that did not get bigger or seem to bother him.