Xeropthalmia
Ulceration of the cornea of the eyes is evident.
Lack of Vitamin A1 in saltwater or A2 in freshwater. Most reported cases come from channel catfish culture. These fish are especially susceptible. This is more common than one imagines, as Vitamin A in food deteriorates over time.
If analysed correctly the outlook is good, but only for those fish that have not been too badly affected.