Having trouble really seeing what is going on in the picture. Better lighting and angle might help. Is it just the one eye, the other is normal?
I would flush the eye out well with sterile saline and make sure there is no gunk, debris or dirt in there. Look for any pus (will be firm and white or creamy colored, kind of cheesy looking) and remove if there.
Look for any injury to the eye, from pecking or getting poked on wire.
Terramycin eye ointment (no prescription required) or plain neosporin can be used in the eye a couple of times a day to prevent infection.
If there are any other symptoms, coughing, sneezing, wheezing, discharge from nares or beak, bubbles in eye, those could be from a respiratory infection which can also cause eye swelling.
I am a first time chicken mama but I notice discharge and black scabs. If I had to guess it looks like dry fowl pox. Do you know where I can get Terramycin without a script? I did clean it with a warm compress and put antibiotic ointment. I do have a flock of 13 so I did remove her and put her seperate. She is not having any breathing issue and is eating and drinking. Any suggestions would be helpful