Pop-Eye (Exophthalmia)
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About this condition
An abnormal protrusion of one or both eyes caused by bacterial infection or water quality deterioration. Eye bulging signals internal inflammation or fluid accumulation, and early environmental improvement along with identifying the underlying cause is important.
Common symptoms
- One or both eyes visibly protruding beyond their normal position
- Redness or cloudiness around the eye
- May be accompanied by raised scales (Aeromonas co-infection)
- Loss of appetite and lethargy
- Reduced vision or disorientation
Common causes
- Bacterial infection (such as Aeromonas)
- Water quality deterioration and accumulation of ammonia or nitrite
- Physical damage or trauma to the eye
- Stress causing weakened immune response
- Overcrowding or excess organic waste
Prevention (husbandry & daily care)
Maintaining clean water through regular water changes and proper filter management is the most effective prevention. Avoiding overcrowding to reduce the risk of injuries from fish aggression is also important, and new fish should be quarantined for a sufficient period before introduction.
Related species guide
→ Browse the species guide for this animalWhen to see a vet
Consider consulting a specialist store within a few daysWhat can a specialist store do?
A specialist aquarium store or experienced keeper will assess the severity and likely cause, providing advice on isolation, water quality improvement, and reviewing the husbandry environment. Unilateral versus bilateral protrusion often reflects different underlying causes and progressions; sharing the history — water change frequency, stocking density, and presence of other symptoms — will help in receiving more targeted guidance. If symptoms are progressing rapidly or are accompanied by raised scales, early consultation is strongly recommended as infection may be advancing.
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