Common Name: Cloudy Eye
Pathogen/Cause: Various organisms (nonspecific), Severe Stress, Malnutrition, Cataracts, Old Age, Hyperproduction of slime due to poisoning, bad water quality, or irritation.
Physical Signs: A cloudy white or grey "haze" over the eyes that may cause blindness.
Behavioral Signs: Associated with loss of vision, also just general signs of lethargy.
Potential Treatment: Investigate if water quality is high first (water changes), then if nutritional needs of that species are being met. Wait at least a week or two before trying any antibiotics, it will often clear on its own if water quality is high.
Other Notes: Frequent water changes a must to improve quality. Test for ammonia, nitrites, nitrates. Cloudy eye is a sign of a number of things, rather than a disease in its own right.