8 young chicks all with similar eye disorder. Considered amonia toxicity. . . could be, but the other 500 seem to be fine. Can't find Opthalmic salve available. Don't know if it would work. Eye is not blistered, just swollen, very irratated some watery. Maybe older bird picking at eye. Maybe scratching irritated eye. Could have had fly contact when very small. Brooder box overwhelmed at first. maybe 5 weeks old now. Any suggestions? All happened together about 8 days ago and all are still living. isolated when there were 4 now have 8.