Betta Fish Popeye (Swollen Eyes): Causes, Prevention, Treatment

Most betta fish owners will agree with one fact they are afraid of one particular disease which is betta fish popeye or swollen eyes. Popeye or swollen eyes is one of the complicated medical conditions that can happen in every fish species. If this condition is not treated timely then it can turn out to be fatal.

Therefore, in this article, I have broadly explained the causes of betta fish popeye and the ways of prevention and treatment.

Popeye in betta can occur due to one reason which is the infection caused by an injury. You can treat popeye very easily by adding salt and melafix after changing the water. To prevent popeye, the foremost step will be to change the water frequently and make sure the quality of water never declines.

Popeye or swollen eyes need to be treated as early as possible. Because the infection might infect another eye which can be dangerous for the betta fish. Therefore, the best solution will be to consult with a vet regarding the treatment of betta fish popeye.

For easing your difficulties, I have explained some of the important steps that you can follow in order to treat betta fish popeye. But first of all, you will need to know the reasons that cause betta fish popeye. Stick to the last word of this article in order to clear up your confusion.

What Are The Important Details About Betta’s Popeye Condition?

Popeye, also known as exophthalmia, is a condition in fish that is characterized by swelling and protrusion of one or both eyes. It is usually caused by a bacterial infection, although it can also be the result of physical injury or a dietary deficiency.

Symptoms of popeye in betta fish include swelling or bulging of one or both eyes, cloudiness or discoloration of the eyes, and difficulty swimming or staying balanced. Popeye can be very serious and may lead to blindness or death if left untreated.

To treat popeye in betta fish, it is important to identify and address the underlying cause. Bacterial infections can be treated with antibiotics, but it is important to consult a veterinarian or a knowledgeable aquatics specialist before administering any medications. Physical injuries should be treated as necessary, and dietary deficiencies can be corrected through proper nutrition.

It is also important to maintain good water quality and hygiene in the betta’s environment to prevent the development of popeye or other health issues. This includes regular changes of water and the use of high-quality water in order to ensure that there is no chlorine, chloramines, and other toxins in the water.

In summary, popeye is a serious condition that can affect betta fish and should be treated promptly to prevent further complications. Proper care, including good nutrition and proper water quality, can help prevent the development of popeye and other health issues in betta fish.

I have discussed details about the factors, treatment, and prevention of betta fish popeye condition in the later part of this article. Read through in order to clear your confusion about this condition.

In treating Popeye, it’s not just about medications but understanding the underlying issue, says Mary McCauley of Mary’s Magic Bettas.

Begin by checking water parameters – ammonia and nitrites at 0, pH stable between 6.4 and 8, and nitrates under 20ppm,’ she advises.

Enhance water quality with regular changes and add tannins like Indian Almond leaves. While antibiotics are crucial for severe infections, use them judiciously.

For immediate relief, consider fasting and epsom salt baths,‘ Mary adds, highlighting the need for a balanced approach and expert consultation.

What Are The Symptoms Of Betta Fish’s Popeye?

Well, there can be a variety of symptoms that can prevail if your betta fish is affected by the popeye condition. Indeed you have to continue the treatment based on the symptoms that your betta fish is showing but you need to have a clear idea about those symptoms first. Therefore, below I have noted all the possible symptoms that you can notice in your betta fish:

Symptoms of fish popeye may include:

Protrusion Of One Or Both Eyes

The bulging eyes in betta fish are the Popeye disease’s most readily recognizable signs. A single eye may experience the unilateral Popeye or two eyes may experience the bilateral Popeye.

It should be treated as an urgency because this symptom usually appears after your betta has had the sickness for a while.

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Cloudiness Or Milky Appearance In One Or Both Eyes

Serious trauma is typically tied to altering eye colors in Popeye’s illness, and unilateral Popeye is more prone to experience them.

A foggy or creamy appearance to bright red and bloodshot are just a few examples of these color alterations. A corneal tear is most likely what is causing the redness. If Popeye is not treated, other fish will suffer from abnormally colored eyes and vision problems.

White Ring Around The Eyes

A white ring or spot around the eye is a fairly dependable clue that your pet bettas may soon exhibit other Popeye sickness symptoms. This is the sign that frequently signals the beginning of a serious disease.

To offer your betta the best chance of regaining from Popeye, begin treatment as soon as you discover this sign if you’re fortunate enough to do so.

Other symptoms that can be noticeable are:

  • Loss of vision or reduced vision
  • Changes in the shape or size of the eyes
  • Difficulty swimming or moving due to the swollen eyes
  • Shortage of appetite
  • Less energetic
  • Less interactive
  • Always lies on the tank floor without any motion

If you notice any of these symptoms in your fish, it is important to take them to a veterinarian or fish specialist for a proper diagnosis and treatment. Popeye can often be treated with antibiotics or other medications, but it is important to identify and address the underlying cause of the condition in order to prevent it from recurring.

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What Are The Factors That Cause Betta Fish’s Popeye?

Popeye, also known as exophthalmia, is a common disease that affects fish and can cause the eyes to bulge out or protrude abnormally. Depending on the signs, Popeye could have a variety of factors. There are two different terms for popeye affecting the eyes. Consider the term “unilateral Popeye” if only one eye is protruding.

Unilateral results from trauma or injuries. In this situation, it would be wise to scan the fish tank of your betta for any sharp edges or things.

Bilateral Popeye, which often results after infection with physical ailments, damages both eyes.


Popeye is a result of infections in addition to trauma. It can be caused by bacterial or fungal infections that affect the eye. These infections can be triggered by poor water quality or physical injuries to the eye.

Infections in betta fish may be brought on by germs, fungi, or parasites. Popeye can affect only one eye or both. Popeye signs are typically the consequence of an illness if you have an aquarium full of other fish who have them.

The majority of Popeye’s are caused by pathogenic bacteria, therefore getting help straight away is essential.

Physical trauma

Physical trauma to the eye can also cause popeye. This may occur if the fish is bumped or injured by rocks, plants, or other objects in the tank. Betta fish frequently suffer from wounds; especially from pebbles and other things in the aquarium which might be problematic.

When you notice an injury, it’s best to remove everything that could hurt them. Then swap out the sharp, plastic decorations for soft alternatives. Additionally, if you have multiple fish in your aquarium, it’s possible that another fish is too responsible. Fish usually engage in combat and harm one another.

Fish are possessive, which makes them aggressive. So, divide the fish into individual tanks if you think they may have suffered injury from other fish.

Nutritional deficiencies:

Popeye can also be caused by nutritional deficiencies, particularly a lack of vitamin A. This can be caused by a poor diet or by problems with the fish’s digestive system that prevent it from properly absorbing nutrients.

Deficiency of nutrients is a common cause of diseases like Popeye. Therefore, you will need to offer your bettas a properly balanced diet of food full of nutrients in order to avoid popeye conditions.

Environmental stress:

Stressful living conditions, such as overcrowding or poor water quality, can also contribute to the development of popeye in fish. In addition, if the betta feels that his territory is overcrowded or other fish are thriving in his territory then it might cause your betta stress and anxiety which can lead to popeye.

Well, I have covered almost all the factors that cause betta fish popeye. However, there can be other factors that can cause popeye, and certainly, you have to provide treatment to your betta fish based on the symptoms.

How To Treat The Popeye Condition In Bettas?

In order to treat the popeye condition in bettas, first you will need to identify the symptoms. After identifying the symptoms then you have to treat the condition based on the circumstances. Below I have explained briefly how you can treat the betta’s popeye that is being caused by injury and infection:

If Injury Is The Reason

Sadly, there is nothing you can do if you believe Popeye was physically harmed. The best part is that since your betta is not in a hazardous area, this type of Popeye becomes less likely to cause death. The actions you should do are as follows:

10 percent of the water in your aquarium should be removed and put into a jar. Epsom salt should be dosed into the jar before adding your betta. On the jar, there will be a suggested dosage and usage guide. Always keep in mind that Epsom salt needs to be dissolved before being added to the jar.

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Before returning your Betta to your main aquarium, you must give it 15 to 20 minutes in the container. To ensure that the water in your aquarium stays warm properly, be sure to balance the container.

In addition, adding aquatic salt to your tank will strengthen your betta’s defenses and hasten its recovery. You should change your water more frequently if you’re applying salt. The experts suggest that salt is the best treatment for curing popeye.

If Infection Is The Reason

Well, if popeye is caused by the infection then the treatment will be completely different. First, your betta has to be moved to an isolation tank as soon as possible.

You ought to make a full water change after you’ve removed your betta from the primary aquarium. This will lessen the likelihood that additional fish may contract the disease.

Ampicillin and aqua salts should be used to cure your betta.

For each and every ten gallons of water, one pill of ampicillin should be used. Before introducing ampicillin to your aquarium, take care to premix it with a small percentage of aquarium water.

You should consult a specialist if you have questions about dosing. Dosages for various drugs will differ. Every three days, completely replace the water, add ampicillin, and tank salts. A 10-day maximum usage limit for ampicillin is required.

Once you’ve administered your betta’s medication in whole, drain the water one further time and then wait to check on him again until you believe he’s recovering.

Keep in mind that Popeye’s eyes may not fully recover for several months.

Finally, you might have understood the treatment process as a whole, however, if you still have confusion then it is recommended to consult with a vet.

Which Medicines Can Treat Betta Fish Popeye?

The medicines for curing the betta fish popeye basically depend on the factors that caused the popeye. In addition, treatment for popeye in betta fish typically involves addressing the condition of the betta fish that is being affected by popeye.

This may involve administering medications such as antibiotics to treat bacterial infections or antifungals to treat fungal infections. In cases where the popeye is caused by physical trauma, treatment may involve providing supportive care such as keeping the water clean and well-oxygenated and ensuring that the fish has a proper diet.

If the popeye is caused by an underlying health issue, such as kidney disease, the treatment will depend on the specific condition and may involve administering medications or making changes to the fish’s diet and environment.

It is important to consult a veterinarian or a qualified aquatics professional for proper diagnosis and treatment of popeye in betta fish.

How Quickly Can Popeye Disease Be Treated In Betta Fish?

A Popeye-infected betta’s bulging eyeballs may not return to usual for several days or even a month.

You don’t need to be concerned about the protruding eyes because they will ultimately return to their usual shape when your betta fish rediscovers its hunger and reports higher physical activity.

What Are The Prevention Methods of Popeye Condition In Bettas?

In order to prevent popeye, you will need to first study all the symptoms that your bettas are showing. It is to be noted that the prevention method for unilateral popeye and bilateral popeye is completely different.  Therefore, I have discussed the two prevention separately in the later part of this article:

Prevention of Unilateral Popeye Condition

Unilateral popeye, also known as asymmetrical exophthalmos, is a condition in which one eye becomes swollen or bulging. It can be caused by a variety of factors, including infection, injury, or underlying medical conditions such as thyroid problems or inflammation.

To prevent unilateral popeye, you should follow these points carefully:

1. Avoid Injuries From Fighting

Betta fish are regarded as violent fish primarily because they are hostile toward intruders and will attack them, particularly fellow male bettas. It’s a recipe for disaster to maintain two male betta fish in the exact same aquarium!

2. Do Not Make Sudden Changes To The Environment

Betta fish have a tendency to run across their aquarium when frightened, running into whatever seems to be in their path.

Switching on the tank light in complete darkness or having something fall into their tank are examples of situations that might not seem as “unexpected” to you as they do to a betta, but which might frighten them nonetheless.

Your betta may scurry into plants, ornaments, or the tank’s walls in response to even little disturbances outside the glass panels. In order to prevent your betta from accidentally hurting itself, try to avoid shocking it.

3. Avoid Unnecessary decorations In The Tank

Putting artificial plants in a betta aquarium can be a poor substitute for living aquatic species, and your betta will be at risk if it finds them.

The tops of plastic plants have the potential to grab their lengthy, delicate fins. These plastic plants can seriously hurt bettas by scraping against their eyes with their sharp edges.

Not just Popeye sickness, but other bacterial illnesses can strike any part of your betta fish’s body that has been harmed by artificial plants.

Bettas prefer to relax and hide behind plants, so go with silky live plants alternatively.

4. Practice Good Hygiene

Keep the tank clean and properly maintained to prevent the build-up of harmful bacteria and parasites.

5. Avoid Overcrowding

Overcrowding can lead to increased stress and the transmission of infections.

6. Provide Proper Nutrition

Make sure that the fish are receiving a well-balanced diet to support their overall health.

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7. Minimize Stress

Try to maintain a consistent and peaceful environment for the fish to reduce stress.

8. Identify And Treat Underlying Medical Conditions

 If a fish is showing signs of unilateral popeye, it is important to identify and treat any underlying medical conditions that may be causing the condition. This may involve administering medications or making changes to the fish’s environment.

It is also important to seek veterinary care if you suspect that your fish is suffering from unilateral popeye or any other medical condition. A veterinarian with experience in treating fish can provide a proper diagnosis and recommend an appropriate treatment plan.

Prevention of Bilateral Popeye Condition

Bilateral popeye conditions can be prevented in many ways. However, you will need to be careful with certain things. I have clearly explained all of the points which can prevent the bilateral popeye condition very easily if followed properly:

1. Water Quality

The main outside thing that impacts how a tank fish’s immune system reacts to illnesses, germs, or fungi is the quality of water. And the reason for this is that poor water quality strains your betta’s immune system, making it susceptible to not only Popeye but also a host of other diseases.

2. Water Change

Water adjustments are crucial for betta fish tanks, particularly if you’re housing your betta in a mini tank (less than Twenty gallons) and if your tank is unprocessed.

By performing twenty percent water changes on a weekly basis, you can maintain the nitrate levels in your betta’s aquarium within acceptable limits and avoid the water in the tank becoming harmful to your vibrantly colored magnificence.

Your betta will be more likely to develop bilateral Popeye if you skip this tank management step.

3. Clean The Filter Medium

The filter medium in your betta fish tank makes an ideal hatching environment for beneficial bacteria, but you need to change or wash it frequently. As trash, uneaten fish food, and other waste accumulate on filter sponges, your tank’s filtration system may not function as effectively as it should.

4. Be Careful with the new additions

Bilateral popeye sickness is not normally spreading, however, bringing in new fish can introduce the primary illnesses that cause it into your betta’s aquarium. Because of this, you must isolate new fish for at least 2 weeks before placing them in a common tank.

Similar to living plants, live plants might hitchhike pathogens, therefore you should carefully clean them with old tank water before putting them in your betta’s tank.

5. Be Careful With The Sick Ones

Your beloved fish should be placed in a quarantine tank as soon as they begin to exhibit clear symptoms of illness (tiredness, loss of appetite, and inability to leave one location). The likelihood of having fewer infectious fish increases with the speed at which you quarantine a sick fish.

So by now, you must have a clear idea about how you can prevent unilateral and bilateral popeye conditions of betta fish. However, it is still recommended to take advice from the vets in order to treat and prevent the popeye condition in your bettas.

Will Popeye Heal On Its Own?

Popeye is not a condition that can heal on its own and requires treatment.

If the cause of the popeye is because of bacterial infection, it can surely be treated with antibiotics. However, if the popeye is due to an injury, it may be more difficult to treat. In some cases, the fish may need to be euthanized to prevent further suffering.

It is important to properly diagnose the cause of the popeye and to seek treatment as soon as possible to give the fish the best chance of recovery. If you are concerned about a fish with popeye, it is recommended that you seek the advice of a veterinarian or a fish health expert.

Do Betta Fish Have The Chance Of Death After Being Affected By Popeye?

Yes, in severe cases, popeye can lead to blindness and even death in betta fish if left untreated. If you notice that your betta fish has popeye, it is important to seek treatment from a veterinarian or experienced aquarist as soon as possible to prevent the condition from worsening and potentially leading to the fish’s death.

With proper care and treatment, it is possible for betta fish with popeye to recover and live a healthy life. However, if the condition is severe and goes untreated, there is a risk of the fish dying.

What Is The Reason Behind My Betta’s Eyes Turning Black?

It’s possible that popeye could cause your betta fish’s eyes to appear black, but there are other potential causes as well. If you are concerned about your fish’s eye color or overall health, it is a good idea to consult with a veterinarian or fish expert for a proper diagnosis and treatment recommendations.

Final Verdict

To summarise, popeye is a condition that causes a fish’s eyes to bulge outward, and it can be caused by a number of factors, including infection, injury, or improper water conditions. If your betta fish has popeye, it is crucial to address the underlying factors and provide appropriate treatment to help your fish recover.

It is important to regularly monitor your betta fish’s health and behavior and to consult with a veterinarian or fish expert if you have any concerns. Proper care, including maintaining good water quality and providing a healthy diet, can help prevent popeye and other health problems in your betta fish.


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Muntaseer Rahman

About Author

Hello, I’m Muntaseer Rahman, the owner of I’m passionate about aquarium pets like shrimps, snails, crabs, and crayfish. I’ve created this website to share my expertise and help you provide better care for these amazing pets.


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