That happens to Sabby every couple months. I just clean it with a wet washrag and that seems to clear it right up. I've taken him to the vet about his eyes before and they didn't really do anything about it, but if it keeps up...well, you know the rest.
Keep an eye on him. If you see any redness coming up it might be a sign of conjuctivitis. Frosty had that goopy eye for a couple of months - on and off - and then a few weeks ago he came with the redness. It got pretty inflamed and we got antibiotics + eye ointment. He recovered well
Frosty got antibiotic together with the eye ointment. It was clavamox for 7 days. It went away for a few weeks..but then it had an even more serious comeback. It went away "for good" with Cephalexin for 14 days. He hated the latter.
The feline herpes virus seems to be present in most cats and could be dormant throughout their life. They say stress may make it act up however. I hope Cujo will recover completely
ps I must add - after reading through Dr Jean's article I remembered that our vet also recommended the L LYSINE. I crushed it and sneaked it in some youghourt since he doesn't like wet food.