I've just hatched six ducklings, most popped out yesterday. This morning I found one keeping its eye closed. On inspection its eye appeared cloudy and a little gunky. There was another with the same condition. So I removed them all from the brood box, cleaned it out and gave them all a warm bath. The eyes cleared up and for most of the day there has been no sign of illness. Now however, one has its eye closed again, though there isn't any sign of discharge, and its peeping with distress whenever it is slightly disturbed.
Should I be as worried as I am? I know young ducklings sleep a lot. But this little guy stands out as especially frail.