"A photo may help. I would try to determine if this is an eye injury or possibly, a respiratory disease such as mycoplasma (MG) or coryza. A peck wound may leave a mark around the eye, and infection may require an antibiotic, as well as cleaning the eye with saline and applying plain Neosporin, Terramycin eye ointment or Vetericyn Eye Gel. Respiratory diseases can be viral or fungal which won't respond to antibiotics, or bacterial or mycoplasmas which may respond to Tylan, oxytetracycline, or Duramycin. Here is a link to read about common respiratory diseases: http://edis.ifas.ufl.edu/ps044 "
Does he have any sneeze, cough, runny nose, or rattly breathing/wheezing that you can see? I would get the pus cleaned out of his eye with QTips and saline, or a manicure tool. The saline eye wash or eye drops/ointment will do a better job. A vet can always prescibe the best antibiotics and eye drops.