How To Cure Popeye In Betta Fish

by Aquarium Scoop | Last Updated: August 24, 2021

It is possible to cure popeye in betta fish, but steps need to be taken to address it because the underlying conditions that cause popeye can lead to death. Popeye is usually caused by an underlying infection or from physical trauma.

In this guide you’ll learn:

  • What is popeye?
  • How can popeye be treated?
  • Is popeye deadly to betta fish?
  • What are the early symptoms of popeye in betta fish?
Treating popeye in betta fish featured image

What Is Popeye In Betta Fish?

Popeye is a condition that affects fishes’ eyes (not just betta fish) wherein their eye bulges out of their sockets due to some pressure behind it. The medical term for popeye is exophthalmia. It can affect one or both eyes. Popeye is usually best prevented rather than treated by ensuring a proper environment for your betta fish. Though it doesn’t directly lead to death in fishes, secondary illnesses possibly caused by the same conditions as popeye can lead to death.

How To Identify Popeye

Popeye can affect one (unilateral) or both (bilateral) eyes. Aside from the obvious bulging eye, popeye can also come with other symptoms such as milky or cloudy eyes, eyes that change color, and red streaks, or a bloodstained eye (often caused by an injury).

Expert Tip

A white ring around your betta’s eyes is usually an early sign of popeye as well as other possible signs of illness such as loss of appetite, lethargy, swelling of other body parts, and avoidance of other fish. 


There are two common causes of popeye in betta fish: an infection caused by fungi, parasites, or bacteria and a physical injury from a fight with another fish, getting caught in a net or hitting something in the tank. 

Bilateral popeye (both eyes affected) is most often caused by an infection while unilateral popeye is most often caused by a physical injury. 

What Causes Popeye In Betta Fish?


If your betta fish has popeye on both eyes and is exhibiting other signs of illnesses then it may be caused by an infection. A white ring around its eyes and other signs of sickness can also signal an infection. If other members of your tank are also exhibiting some sort of illness then it is most likely an infection. 

At this point, it’s good to check your water quality parameters to see if anything is off. Poor water conditions are usually what causes any infections in fishes. Common betta fish diseases such as ich or velvet are also caused by parasitic or bacterial infections. 

Physical harm

Bettas can get territorial and aggressive so they may get in a fight with other tank inhabitants or fishes. This can cause some sort of physical injury or trauma to your fishes especially their eyes. If your betta has unilateral popeye (only one eye is affected) then it is mostly from an injury. Other causes of injury include hitting objects in your tank or perhaps getting caught too roughly in a net when taken out during tank cleaning. 

How To Treat Popeye In Betta Fish

Treating popeye in betta fish will depend on its cause but in either case, it will require the isolation of your affected fish in a quarantine tank for better treatment. 

Treating physical injury related popeye

Popeye caused by physical injury is a bit easier to treat since the water environment or water quality most likely does not have a problem. Your betta fish’s immune system is probably in good shape and all you would need to do is help it recover by treating it to an Epsom salt bath.

  1. Take about 10% of the water from your main tank and transfer it to your quarantine container/tank.
  2. Dissolve Epsom salt into the container according to the instruction (general rule is a tablespoon of Epsom salt per gallon of water).
  3. Carefully add your betta into the container to prevent further injury.
  4. After a 10 minute soak, return your betta carefully back into your main tank. Try to acclimatize it well since the water quality between the two tanks will be different. You can do this by slowly replacing the water in the quarantine tank with your main tank’s water or by dipping the quarantine container into your main tank for a few minutes before putting your betta fish back in.
  5. As an alternative, you can use aquarium salts into your whole main tank which will also help improve the immune system of the rest of your fish. Make sure to perform more frequent water changes during this treatment. 

Treating infection related popeye

Popeye caused by an infection is a bit more complicated since you will also need to check for signs of infection on the rest of your aquarium fish. You should also test your water quality and adjust for any parameter that may be off. A full water change after isolating your affected fish and a deep clean of your main tank after treating your fish is also best. 

  1. Set up a quarantine tank with the proper water conditions for a betta fish (or your normal aquarium water conditions in your main tank).
  2. Move your affected betta fish into the quarantine tank very carefully.
  3. Perform a complete water change in your main tank to reduce the chances of your other tank inhabitants getting infected.
  4. Treat your affected betta fish with an antibiotic (ampicillin or tetracycline) and aquarium salt. Check for the correct dosage for your specific medication. It’s best to ask a vet if you are unsure. Usually, 1 capsule of ampicillin is good for 10 gallons of water. If you cannot make sure of the dosage, always dose less. Premix the medication into a small amount of water from your quarantine tank before adding it.
  5. Perform a complete water change in your quarantine tank every 3 days and re-add the medication and aquarium salt.
  6. Do this treatment for a maximum of 10 days (or the recommended duration). If your betta fish starts to improve, perform one last water change and observe it before returning it to your main tank. Popeye can take a long time (months) to return to normal so be patient.

What Are The Symptoms & Early Signs?

White ring around the eyes

A white ring can sometimes develop around the eyes of a betta fish and is one of the few early signs. If you notice this, proceed to treatment immediately to prevent it from getting worse.

Lethargy, less activity, loss of appetite and other symptoms

Popeye can be caused by poor tank conditions that lead to infections. Common symptoms of parasitic, bacterial, or fungal infections include: lethargy, less activity, and loss of appetite. Watch out for other symptoms of infection or illness such as dropsy or the swelling of the tissues of your fish.

Dull colors

Betta fish can sometimes exhibit duller coloration when they are ill. This symptom can sometimes accompany the occurrence of popeye, especially if it’s caused by an infection.

📚 Read More >> How To Stop Betta Fish Color Loss

Eyes changing color (milky or cloudy eyes)

Before the betta fish’s eye becomes swollen or bulges, it may change its color as fluid builds up. It can look cloudy or milky which is a sign that something may be wrong. 

Red streaks or a bloodstained eye

If your betta fish was in a fight or was physically injured from hitting something in the tank or being handled with a net, then it may develop red streaks or blood stains on its eye before the bulge or popeye develops. 

Is There A Cure To Popeye In Betta Fish?

Yes, popeye in betta fish can be cured. If it is an injury related popeye then you can help your fish recover by using aquarium or Epsom salt which is a general tonic for ailments in fishes. 

For popeye caused by infections, an antibacterial or antifungal such as ampicillin or tetracycline in addition to the salt treatment is needed. Make sure to check the dosage of your medication before adding it into the water. In both cases, it is best to keep your affected fish in a quarantine tank for treatment. 

Is Popeye Contagious To Other Fish?

The condition itself is not contagious but the causes of popeye, specifically infections that can arise from poor water quality is contagious. Parasites, bacteria, or fungi in your tank water that can cause popeye can affect other fishes in your tank. 

If you don’t suspect physical injury as the cause of your betta fish’s popeye, you should isolate the affected fish to treat it better even if it is not contagious. The poor water quality or the infection in the water can prevent it from recovering quickly. Then address your tank’s water conditions as soon as possible to prevent your other fishes from contracting the same infection.

How To Prevent Popeye In Betta Fish

Prevention is definitely better than cure, especially with a condition such as popeye. Preventing the two major causes (physical injury or infection) is actually quite simple. 

Reduce The Chance For Infection

Keeping on top of your aquarium maintenance is the best way to prevent any infection. Poor water quality leads to a number of diseases and can lower the immune system of your betta making it harder to recover from other illnesses. 

1. Maintain good water quality

Follow all the best practices that help maintain good water quality in your aquarium. Make sure your filter is in good condition and make sure you are not overstocking your aquarium. An overstocked aquarium will make it hard for even the best filter to keep clean. Your tank’s bioload may be increasing too quick for your filter to keep up. Also make sure that you use dechlorinated water in your tank. 

If you plan to add any plants, decorations, other fish, or anything to your tank, make sure these are disinfected to prevent any contamination or parasites.

2. Keep a good water quality monitoring schedule

Sometimes, changes in your water quality may not be easily seen visually, so it’s good to always check parameters such as water chemistry, pH, and temperature. Nitrate, ammonia, and nitrite levels should be very low close to 0 ppm since these can be toxic to fishes. High temperatures can hasten the build up of bacteria and the wrong pH levels can also affect the community of good bacteria in your tank. Make sure you perform a test with an aquarium kit to check your tank’s water quality every 1-2 weeks.

3. Keep a good cleaning schedule

A good water changing and cleaning routine will help keep your tank in shape. Partial or complete water changes should be done routinely depending on the size of your tank. Bigger tanks sometimes require less frequent water changes. Make sure to monitor the water quality as you change your water.

4. Isolate any ill fishes immediately

If you notice any of your fishes showing symptoms of an illness, make sure to isolate them in a quarantine before they affect the other fish or tank inhabitants. Keeping them isolated will also help you treat them better.

Prevent Physical Injuries That Cause Popeye

1. Check your plants and other tank furniture for any sharp parts

It’s generally best to stay away from plastic plants that are too hard for bettas and other fishes. Opt for silk ones available in most pet stores if you do not want to take care of real plants. If you have live plants, make sure their leaves, stems, or roots are pruned well so as not to injure your betta fish.

2. Practice extra care when handling your betta

If you need to handle your betta fish, make sure you practice extreme care especially when using a net. Try not to startle them too much as well since they can panic and become frantic, causing further injury.

3. Check for aggression in your fish community

Sometimes fishes can become territorial or aggressive even if they are usually docile so observe for any behavioral changes in your fish. Try to keep your tank community fishes the same general size to prevent any bullying. Watch for any fin nips that may indicate aggression.

4. Make sure your aquarium lights are not too harsh

Aquarium lights may be too harsh when turned on quickly and cause your betta to become shocked and swim frantically causing it to hit some of your tank furniture, leading to an injury. Make sure you turn on your aquarium lights softly. It’s better to turn on the lights in the room and wait for a few minutes to get your fishes acclimatized before turning on the aquarium lights. 


Will Bettafix cure Popeye?

Yes and no. Bettafix is an antibacterial remedy meant for a variety of diseases caused by bacterial infections such as: wounds, ulcers, mouth fungus, fin rot, and tail rot, slimy patches, and cottony growths. It can be effective against popeye if it was particularly caused by bacterial infections. 

However, it’s still good to address the root cause of popeye and adjust accordingly. For example, making sure the water is clean and keeping an eye on the water quality is a good countermeasure if your betta fish has popeye. This will help them heal in addition to any medication. Most of the time, a more potent antibiotic medication in addition to an aquarium salt treatment is proven more effective against popeye caused by an infection.

Will Melafix cure Popeye?

Melafix is a catch-all cure for many ailments in fishes caused by bacterial infections. It can help with popeye but it’s also good to check the underlying conditions or possible causes of your betta fishes’ popeye so you can prevent or address them specifically.

If your betta fish’s popeye is caused by anything other than bacterial infections then Melafix may not cure it. It’s also good to clean your aquarium’s water so that you can help your fish recover faster in addition to any medications you give it. A more potent antibiotic medication in addition to an aquarium salt treatment is proven more effective against popeye caused by an infection.

How do you treat Popeye in betta fish?

The best treatment would be to make sure that you have clean water with the proper conditions (water chemistry and water parameters) for your betta fish. This will help eliminate any bacterial build up that may have caused the infection and help your betta fish recover better if it was caused by an injury. 

It’s best to isolate your affected betta fish to treat it better. Usually a salt bath is good to increase its immune system but if the popeye was caused by an infection, an additional antibiotic treatment is required. Make sure your betta fish is in clean water during its recovery.

How long will my betta fish live if they have popeye?

Your betta fish may still live for a long time even with popeye. In fact, it’s not uncommon that betta fish still survive even if popeye causes their eyes to rot and fall off.

Bettas and other fish with popeye most often die from secondary ailments that cause popeye such as poor tank conditions. Especially if these diseases progress too much before treatment. This is why it’s quite important to address the causes of popeye to prevent it and the development of other illnesses. 

Can betta fish die from Popeye?

Yes and no. Popeye may not always be the direct cause of death in betta fish. Popeye is usually caused by poor tank conditions that often lead to other illnesses and infections that are more serious. It’s these diseases such as septicemia and Hexamita infections, in addition to popeye that probably causes death in fishes. Again, swift action against the probable causes of popeye will ensure your betta fish does not get other illnesses that can cause it to die.


Popeye may seem like a scary condition your betta fish can have but it can easily be prevented and treated. It has two major causes: physical injury or an infection. Both can be prevented by ensuring a healthy environment for your fish with the proper tank conditions. Treatment usually involves the use of Epsom or aquarium salt and/or an antibiotic medication depending on the cause of popeye.

Further reading

Overview article on betta fish:
Siamese fighting fish

Care guides and articles:
Betta Fish Care Guide
Your Betta Needs More Than a Bowl – Veterinary Medicine at Illinois
Betta Fish: Facts and Why They’re Not ‘Starter Pets’ | PETA

A thread on treatment:
Bettafix works on pop-eye, right?

Comprehensive list of betta fish diseases:
Betta Fish Diseases – How To Treat A Sick Betta Fish |