Welcome To BYC
It's hard to tell what's going on by your photos.  Can you get some more that are clear?
From what I can see, they have feather loss from picking and/or mating.
How much space do you have in your coop/run and how many birds do you have in that space?
What do you feed including treats?
Your title mentions mites, lice and gleet?
Do you see mites and lice on your birds?  Look them over for crawling bugs, inspect under their vents for bugs at night.  If you see any, then treat with a Permethrin based poultry dust or spray in 5-7 day intervals, treat your coop as well.
Gleet is a yeasty discharge from the vent, do you see that? Photos?
Thanks!