Betta Cloudy Eye

Betta Fish Cloudy Eye: Causes, Treatments, And Preventions

Sharing is caring!

Betta fish are quite sensitive to water conditions and stress, but they can get sick from time to time even when given the very best care by their owners.

Cloudy Eye is a condition that quite commonly affects betta fish. That’s a frightening thing for you and is distressing for your pet too. In this comprehensive guide, we discuss cloudy eyes in bettas, including the causes, treatments, and how to prevent the problem from occurring in the first place.

What is Cloudy Eye?

Cloudy Eye is a disease that makes the lens in your betta’s eye become opaque, giving your pet’s eyes a cloudy appearance, hence the condition’s common name. Depending on the cause of Cloudy Eye in your pet, the condition is often treatable, and your fish should make a full recovery.

However, the condition has numerous potential causes, so it’s crucial that you identify the cause of the problem to find the most effective treatment.

First, let’s find out how your betta’s eyes work.

How do betta’s eyes work?

Before we talk about the causes of Cloudy Eye and what you can do to fix it, let’s find out more about how fishes’ eyes work.

Many times, your betta could be sickening for something, and you have no idea that there’s a problem until he’s really ill. However, very often, the first warning signs of fish diseases can show themselves in your betta’s eyes, specifically, if the shape, clarity, or color of the eyes changes. Many early signs of diseases show up more clearly on the eyes’ clear tissue than on the creature’s body, and understanding how these optical changes can be used to spot and diagnose illness in your betta can be extremely helpful for aquarists.

image001 1b9ad8f0bf0371ba986ee211f3e48a22

How your betta uses his eyes

Your betta buddy’s eyes work in much the same way as most creatures’ eyes do:

  • Light enters the eye
  • The pupil focuses the light
  • The light falls onto a receptor that creates an image
  • The image is interpreted by the fish’s brain

The specific gravity of water is different from that of air. So, because a fish is adapted to live underwater, it cannot see properly out of the water. A betta’s eyes are situated on the sides of his head, enabling your fish to see to each side of his body, almost directly behind, and almost directly in front of him. However, that interpretation of two separate images at once means that the fish lacks depth perception. Most fish species, including bettas, do not have eyelids. That can leave their eyes vulnerable to injury and is one crucial reason why you should never put sharp objects in your betta’s aquarium.

Predatory fish, such as bettas, need a certain amount of depth perception to that they can see their prey more clearly. Therefore, the betta’s eyes are placed slightly more forward on his head to compensate. However, you can exploit the fish’s poor depth perception by using two nets to catch him and approaching from two different directions at the same time.

Cases of blindness in wild bettas are catastrophic for the fish, as he will be left unable to hunt and find food. Clearly, that doesn’t apply to your tank-kept betta, although you may need to hand-feed him to make sure that he gets enough to eat.

Betta Cloudy Eye

Causes of Cloudy Eye

The causes of Cloudy Eye in fish are many and varied.

Internal parasites

Sometimes, your betta may be attacked by internal parasites, including flukes and protozoa. These parasites usually attack wild fish, although it’s possible that the creatures may be introduced to your home aquarium by hitching a ride on plants or with live food. That’s why you should always wash anything that you add to your aquarium with an antibacterial and antiparasitic solution before introducing it to the tank.

Infected fish develop cloudy, enlarged eyes, sometimes with microscopic worms evident in the eye. Affected fish usually become blind in the affected eye, and may also develop a cataract in that eye.

Unfortunately, although you can treat the aquarium water to kill the parasites, your betta cannot be treated once the damage is done, and he will remain blind.


Just like people and other pets, fish can suffer from cataracts. Cataracts are a common eye disorder, especially in older bettas, that cause the lens of the eye to become opaque and cloudy.

Cataracts can be caused by parasites (see above), genetic factors, or incorrect feeding. There’s no treatment for cataracts in fish.

Bacterial infection

It’s crucial that you don’t have any sharp or abrasive objects in your betta’s tank. Tank decorations should be smooth, and if you don’t use live plants, choose soft silk ones instead, rather than plastic. Anything sharp is a potential source of injury for your curious betta.

Eye injuries are a common entry point for bacteria, which can cause an infection, leading to permanent eye damage, loss of vision, and cloudiness. You can save your betta’s sight if you spot the injury early. Put your injured betta fish into a quarantine tank, and treat the water with a proprietary antibiotic to cure the infection.

Nutritional deficiencies

A correct, balanced diet is essential for your betta if he’s to stay healthy, lively, and thriving. Any dietary deficiencies, including a lack of vitamin A, can adversely affect the health of your fish’s eyes.

So, make sure that you give your betta a balanced diet that includes high-quality tropical flakes, betta mini pellets, frozen meaty foods, and rehydrated freeze-dried bloodworms.

Poor water quality

By far, the most common cause of Cloudy Eye in aquarium-kept fish is poor water quality, particularly when the water pH falls too low.

Even one betta fish in a very small betta tank or bowl will generate a lot of waste, and one of the by-products of biological filtration is acids. Eventually, acidity causes the pH of the water to fall, and that can cause health problems for your pet, including Cloudy Eye.

The solution to the problem is pretty straightforward, and that is to test your aquarium water regularly. If the pH drops below 6.8, carry out more frequent water changes, testing the water every day for a few days to check that the pH level remains stable. You should also test your tap water, as you may need to add a pH buffer treatment as well as a de-chlorinator before adding the water to your tank.

Once the poor water quality issue has been resolved, your fish’s eye problem should clear up without further intervention or permanent damage.

Symptoms of Cloudy Eye in bettas

The primary symptoms of Cloudy Eye in betta fish is the appearance of a gray or opaque film across your fish’s eye or eyes. You may also notice a build-up of mucus on the fish’s body in response to the infection.

Your betta may have problems swimming and finding food, potentially losing his appetite. Also, your fish may become stressed by his predicament and may lay around on the substrate or hide in a cave.

Betta Cloudy Eye

Is Cloudy Eye contagious?

Cloudy Eye is not generally contagious to other fish in a community setup, but that does depend on what’s causing the problem. For example, if your betta has developed congenital cataracts, none of the other fish in his community are likely to be affected.

However, if the problem is poor water quality or inadequate nutrition, you need to act quickly to remedy the issue, following the guidelines above. Also, if you notice multiple fish with big eyes in the community, that could indicate the presence of parasites or some other disease that you should treat with a suitable over-the-counter product.

How to treat Cloudy Eye

First of all, if your betta fish lives in a tank with other fishes, ideally, you should move him to a separate quarantine tank.

Once your fish has been transferred to the quarantine tank, you should add a small amount of aquarium salt that you’ve already dissolved in a little tank water. You’ll need to add one tablespoon of salt per five gallons of water. To reduce your pet’s stress and help to build up his slime coat, add some stress coat water conditioner as per the manufacturer’s directions. Remember to top up the stress coat and salt when you carry out partial water changes.

While your betta is living in the hospital tank, carry out some partial water changes on your main tank. The larger your aquarium, the less water you need to change. So, if you have a 5-gallon betta tank, change 50 percent of the water every three to four days. If the tank is 10-gallons, change only 25 percent of the water every three to four days.

When your fish shows signs of improvement, you can move him back into the main aquarium.

How to prevent Cloudy Eye

Follow these guidelines to keep your betta healthy and prevent him from developing Cloudy Eye:

  1. Test your aquarium water at least once every week. Ammonia and nitrite levels should both be zero, and nitrates should be no higher than 20 ppm (parts per million). If those levels rise, carry out a partial water change so that the correct parameters are achieved.
  2. Make sure that you perform a water change every week, as well as vacuum the gravel to remove fish waste, uneaten food, and general detritus.
  3. Periodically, remove all decorations, including silk plants, and give them a thorough clean.
  4. Install a good quality filtration system that keeps your tank clean and maintains good water quality in your pet’s home. The system should include mechanical, biological, and chemical elements. The mechanical part of the filter extracts floating particles of debris from the water, the biological element processes fish waste, etc., and the chemical filter removes heavy metals and other chemical nasties.
  5. Remember to clean the filter every month and replace the cartridges when required.
  6. Don’t overload the filtration system by overstocking your tank. As a general rule, you can have 1 inch of fish per gallon of water.
  7. Never keep your betta in a vase or aquarium smaller than 5 gallons. The water will quickly become dirty, the pH could change, and your pet could develop health problems as a result.
  8. Feed your betta a nutritious, correct diet that contains plenty of meaty protein.
  9. Take steps to make sure that your betta doesn’t become stressed, weakened, and more vulnerable to disease. So, make sure that his tankmates don’t harass him, make sure that the water temperature in the tank is correct and remains stable, and provide plenty of decorations and toys to prevent boredom. Did you know that bettas can change color when stressed? Check out this fascinating article to find out more!

Final thoughts

If your betta fish develops Cloudy Eye, do some detective work to find out what’s causing the problem, starting with a water test. If the water conditions in the aquarium are not within acceptable parameters, rectify the problem through partial water changes. While you’re treating the tank, put your betta into a hospital aquarium and treat him with aquarium salt and slime coat.

Some cases of Cloudy Eye cannot be treated, and your fish will likely lose his sight. However, the most usual cause of this unpleasant condition is poor water quality, which is very preventable if you keep your aquarium clean and correctly maintained.

Sharing is caring!

Leave a Comment

Your email address will not be published. Required fields are marked *