I have noticed that one of my Giant danios eyes seem to be bulging...which 
has progressively gotten worse...to the point where one of the eyes has 
dissappeared. Obviously the fish was in some distress having only one eye 
and rapid breathing at the surface. No other fish, including other GD's have 
been affected.
What  causes this rather grotesque manner of death and what can I do to 
prevent other following the same fate?

Smudge