It is weird, I'm wondering if the coryza virus just hit them in different ways? The first one it was a swollen eye like yours, no respiratory or other symptoms, no smell. Then second just didn't seem to thrive so I would seperate her and bring her back to health but the last time she just didn't make it. The pullet I just lost, suddenly became lethargic, only two days and she died. No other symptoms like respiratory etc. I have another roo who became gurgly and raspy that's when I treated them with Tylan and tetracycline over a month ago, he quickly recovered and has been fine ever since. Last night we spent 4 hours shoveling, raking, scrubbing the barn. Sprayed all surfaces with vinegar and water, replaced sand and limed everything, we called the farm vet and they said if we used bleach we'd have to keep chickens out x2 days. Lime will kill a lot of viruses, fungi etc. It has been very hot and humid here last few weeks. We also put fans in barn for better circulation of air. I hope this helps knock down whatever is going around. Your chickens with Coryza, they are ok now? Thanks for your input, it's always helpful to hear others experiences, it seems like chickens are so hard to diagnose and treat sometimes no matter how hard we try.