It could be a swollen sinus from a respiratory infection such as mycoplasma gallisepticum or MG/CRD. There are several that can cause swelling of the eye and face. Are there any other symptoms such as sneezing, watery eyes, nasal drainage, or rattles or wheezes when you listen to their chest? Vet Rx won't do much, but won't hurt. These diseases are chronic, meaning the chicken never fully gets over them completely, and they leave the chicken and all flockmates carriers for life. If you choose to treat with antibiotics such as Tylan50 injection, and not to cull this chicken, close your flock to any birds in or out. Here is some info on MG, coryza, ILT, and others: http://edis.ifas.ufl.edu/ps044
Thanks for the info. Just an occasional sneeze from someone in the flock. I have 11- 1 year olds and 4 -2 month olds that I hatched. They all seem fine except for this one with a swollen face. I will check out the link. I do have Tylan 50.
I would separate this one out for a couple of weeks (treatment and recovery) and keep far far away from the 2 month olds. If you need a dosage for the Tylan50, it is 1/2 ml under 5 lb, 1 ml over 5 lb once a day into the breast muscle for 5 days.