Oscar Fish Cloudy Eyes – Is it Popeye disease?

The onset of cloudy eyes in aquamarine fish is quite common, and it can occur due to many factors. The cloudy eye syndrome is more commonly known as the Popeye disease.

What is Popeye disease? The Popeye disease which is also called exophthalmia is caused usually by an infection in which the eyes of the fish get swollen and bulge outwards. They may seem cloudy as well. This condition should be treated immediately; if left untreated, the fish ultimately goes blind.

How to Treat Popeye (Video)

This article will cover all aspects of the popeye disease and its control.


Fish that are affected by this condition display swelling in one or both eyes. This is usually due to the leakage of fluid into the area present behind the eyeball.

The eye might get discolored or showcase a cloudy appearance. In some cases, the eye might even appear bloodstained. This occurs when the fish has been suffering from a physical injury.

Causes of Popeye disease in fish

Poor water quality, injury, and bacterial infections are all common culprits of Popeye. Tumors, Vitamin A deficiency, and gas embolism are some of the less common reasons.

These conditions can also be caused by gas bubble disease which comes into being as a result of excess levels of oxygen and nitrogen in the water (Super saturation).

Supersaturation is the phenomenon that occurs when the pressure of the gas outside the water is less than the pressure of the same gas in the water, and it leads to gas being pulled too quickly out of the bloodstream of the fish leaving in its wake gas bubbles.

This is caused when filters blow air directly inside the tank from the outside and from the pressurized tap water, which was not mixed in the first place and ultimately leads to an excess of oxygen in the water.


There is a very important step that  you ought to carry out which is to take out the infected fish and separate it from the other healthy fish. It is challenging to identify the right course of treatment without knowing the culprit.

In order to carry out a general sweep, change the water daily or use Epsom salts to draw the fluid out. This has been known to give good results. Use one tablespoon of Epsom salt per 5 gallons of water for at least four days or even longer if it is required.

Epsom salt is not Sodium Chloride but Magnesium Sulfate. If you think that the water quality is poor, then carry out at least a 50 percent of water change as soon as you can.

If you have added a new item to the aquarium recently, then check it intensely as it may be poisoning the environment or secreting hazardous chemicals.

If you are using a poor water conditioner, then it’s time to invest in a high-quality one; a water conditioner that has been given a high rating by other aquarists.

Test the water for nitrates and ammonia. If the water gives a high reading then carry out a 50 percent water change again and continue to carry out 15 to 20 percent water changes at least 2 to 4 times a week. Do this until the water readings are normal and correct.

Overcrowding is another major factor behind the high concentration of toxic materials in the water. Try finding your diseased fish a separate better home. Dead fish and decaying food also contaminate the aquarium. Search for any dead fish and remove them. Also, make sure that you do not overfeed your fish.

Antibacterial medicine for bacterial infections

If Popeye is being caused by a bacteria, then use an anti-internal bacteria medicine for treatment like API MELAFIXMaracyn 2 and ESha 2000. 

You can purchase all three of these medicines by clicking the affiliate link above.


Examine your fish every few days to be on top of their health issues. Also, make sure that the aquamarine water is clean and test the water for ammonia and nitrates every week.

Before introducing any new fish into the fish tank, quarantine it for at least 2 weeks to be on the safe side; as fish can carry parasites or bacteria and endanger the health of your old healthy fish.

Related questions

How long does it take the swelling in the fish to diminish? It takes about a few weeks or even months, depending on the severity of the situation

Can Popeye disease prove to be fatal? No, Popeye disease does not necessarily kill the fish, but it does make it go blind.

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