What are betta fish cataracts?

In this blog, we will discuss cataracts in betta fish. We will discuss reasons and treatment of cataracts too in this blog.


In this blog

  • What are betta fish cataracts?
  • What are the different stages of cataracts in betta fish?
  • What are the reasons for cataracts in betta fish?
  • How to treat a betta fish with cataracts?
  • How to prevent cataracts in betta fish?
  • Are cataracts common in betta fish?
  • Is betta fish cataract contagious?
  • Summary 
  • Frequently asked questions
  • Reference

What are betta fish cataracts?

Like other fish, betta fish can also suffer from cataracts, a common eye disorder that causes the eye lens to become opaque. 

A nutritional imbalance may cause cataracts, while parasitic infection, genetics or other unknown factors may also contribute.

Cataracts are more common in community tanks than in individual tanks. Unfortunately, there is usually no cure for cataracts.

What are the different stages of cataract in betta fish?

Cataracts can be divided into primary & secondary stages. Primary cataracts are caused by opacity of the lens, while secondary cataracts develop as a result of other intraocular diseases.

Cataracts usually produce an opacity in the lens, either partially or completely. In the early stages, small white spots are seen in the center of the lens and in more advanced stages, the entire lens is affected. Sometimes white circles are seen in the lens.

What are the reasons for cataract in betta fish?

The reasons for cataracts in betta fish are:

  • Betta’s genetic predisposition.
  • Nutritional imbalances in bettas.
  • Parasitic infection in bettas.
  • Temperature fluctuations in bettas tank.
  • Betta cataracts due to old age.

Bettas genetic predisposition

If you are planning to get a new betta fish, then you should know everything about their genetics, or get it from betta breeders who are aware of their genetics. Bettas with good genetics will have great finnage coloration, longevity, and sound health.

If you happen to get a betta fish with poor genetics, then be prepared to face consequences like eye diseases, early death, and poor health.

Nutritional imbalances in bettas

To keep your aquarium fish healthy, provide them with a nutritious diet that meets their specific nutritional needs.

It is easy to give your betta the right diet, but you may need to read labels and keep track of how much and how often you are feeding your fish.Feeding your betta a variety of foods will enrich and stimulate your betta.

In betta fish, too much protein or carbohydrates can lead to the development of cataracts, so it is important to keep carbohydrate intake in moderation and to get the right vitamins and minerals.

If you are overfeeding or underfeeding your bettas, they will encounter various health problems including cataracts.

Parasitic infection in bettas

A cataract can also be caused by infection. There are many types of infections that can be caused by different types of organisms. If your betta has a cataract, it is most likely due to parasitic infection.

Parasites are small creatures that live on the tiny blood vessels of the different living things that bettas fish eat.

There are many different types of parasites that can infest a betta fish. Tapeworms are probably the most common parasite affecting bettas. They can be very destructive and annoying for your fish.

It is mostly possible in community tanks or overcrowded tanks. It is always important to quarantine a new fish at least for 2 weeks in a quarantine tank before adding them to the community tank.

Temperature fluctuations in bettas tank

Betta fish come from warmer waters and thrive well in warmer temperatures. If there are temperature fluctuations in bettas tanks, they might get temperature shock or may get varieties of infection including cataracts. 

It is therefore important to maintain ideal temperatures in bettas tanks to avoid such eye disorders.

Betta cataracts due to old age

As your bettas get older, they may develop cataracts. The older a fish is, the more likely it is to experience cataracts. If you notice that they are over two or three years old, their chances of developing cataracts increase.

How to treat a betta fish with cataracts?

The cataracts in bettas are not treatable. Early detection and quick action will have your betta healthy in no time. Follow the steps below to ensure a rapid recovery:

  • If you have kept your betta fish in a community tank then isolate them to a hospital tank for the treatment.
  • Put your betta in a hospital tank set up with the appropriate water conditions, heating, filtration, lighting, and covers for your betta to hide within.
  • If you want to avoid the community spreading an infection, you should isolate the fish.
  • You can treat them using some medications by consulting your vet.

How to prevent cataracts in betta fish?

Cataracts are not treatable, but prevention is better than cure. Do few things religiously to keep your betta fish healthy and safe:

  • It is important to regularly change your betta’s tank water to keep it at a healthy level. In smaller aquariums, water changes must be larger and more frequent. And for larger tanks, you only need to make a 25% weekly change in water volume.
  • Water quality must be checked regularly to ensure that pH and ammonia levels remain stable.
  • Keep the tank clean and vacuum your substrate regularly to remove feces and leftover food from bettas tank to avoid ammonia pollution.
  • Excessive feeding of your betta fish or feeding of the wrong food can lead to health problems and water quality problems.It is very important to provide them with food that is of good quality and enough to satisfy their hunger.
  • Do not overstock or overcrowd your bettas tank. If your tank is smaller than five gallons, your bettas may not be able to live healthily in it. They can survive in smaller tanks, but they will not be healthy.
  • We recommend removing any sharp objects or decorations from your aquarium so your betta fish with cataracts can stay safe. If you still want ornaments, consider replacing them with either live plants or silk plants.
  • The best way to keep your betta fish healthy is to learn as much as possible about their natural history, genetics and proper care.This includes knowledge about their food, aquarium care, fish handling, and tankmate aggression.
  • If you find cataracts in your betta fish, contact your veterinarian or fish health professional as soon as possible so that the problem can be identified and effectively managed.

Are cataracts common in betta fish?

A cataract is a type of lens that becomes opaque, making it difficult for light to pass through. While this condition is not common in bettas fish, it does occur from time to time. 

The cause of cataracts is nutritional deficiency, trauma, or hereditary factors.A balanced diet including fresh food can help prevent cataracts in betta fish.

Is betta fish cataract contagious?

Cataracts are not contagious. However, if the water conditions in the betta fish tank have caused one fish to develop cataracts, you can be assured that the other fish in the tank will also develop the condition until the water conditions improve. 

If you have a betta in a community tank, it’s important to take rapid actions to prevent cataracts from developing in more than one fish in the tank.

Are betta cataracts deadly?

Any disease not treated is likely to be fatal, although cataracts are least likely to cause death. Your betta fish will quickly recover as long as you adjust the water quality levels and feed your betta fish a balanced diet.

If the symptoms get worse or new symptoms occur, it may not be cataract, so you’ll need to investigate further. If necessary, you can obtain a diagnosis from a local aquatic center.

If you detect a cataract early, it can easily be treated and won’t be fatal.


Cataracts are changes in the clarity of the lens, making it appear cloudy and the opacity of the lens leads to a reduced vision in bettas.

The main cause of cataracts in bettas is age. As bettas get older, the lens in their eyes begins to deteriorate, leading to clouding of their vision.

There is no treatment for cataracts in betta fish. Eye drops are of no use since they will come off as soon as your fish swims away. Providing clean water and a healthy diet can help prevent cataracts.

If your betta is suffering from cataracts there isn’t much you can do to treat it, so all you have to do is help your betta live with it.

Frequently asked questions

Is there any treatment for cataract in bettas?

Betta fish cataracts do not have any treatment.

Are cataracts more common in old bettas?

Yes, cataracts are more common in old bettas.

What are the main causes of cataracts in bettas?

The main causes of cataracts in bettas are:

  • Nutritional imbalances
  • Genetic predisposition
  • Temperature fluctuations
  • Water salinity fluctuations
  • Parasitic infections