What Does It Mean When A Fish Eyes Turn White?

William Shakespeare once said the eyes are the windows to your soul. While this statement carries more meaning for us humans, it plays an important role for our aquatic creatures swimming in our aquariums, and in helping you to investigate what is really going on with them.

A fish eyes turn white when they have parasites on them.  These parasites will cause cloudy eyes for your fish, There will also be other symptoms you can look out for such as white spots on the fish’s body.

What Does It Mean When A Fish Eyes Turn White

The best way to remove parasites from your tank is to use a anti parasite treatment which you can get on amazon

Endlers livebearers Fish Care Guide video

When the light enters and is focused on the pupil, it is received by an internal reception which creates an image and is sent to the brain for interpretation.

And just as the way humans suffer from various eye defects due to several unfortunate circumstances, fishes are not left out.

If you have noticed the eyes of your fish going white and worried about it, you just happen to be in the right place and reading the right article.

Cloudy eyes for fishes is a terminal disorder that causes the pupils of fishes to become white and opaque. This is a condition commonplace amongst freshwater fishes such as betta, catfish, and discus fish. However, saltwater fishes like yellow tang, ocean sunfish, queen angelfish also experience cloudy eyes but in extremely rare conditions.

It is important to also point out that some rare species of fishes also feature a normal cloudy luster to their pupils which is totally cool. But you should be concerned if the pupils of some of the fishes in your tank begin to turn white.

Contrary to what most aquarists may put forward, Cloudy Eyes is not a contagious condition. Rather, it is only a symptom of a disorder that if untreated will result in blindness and inability to find food. If it persists untreated, it could lead to death. You don’t want that.

Now that we’ve put a name to the condition, what are the common causes behind it?

Poor Water Quality in the Tank.

One of the common reasons behind Cloudy eyes is poor water quality in the aquarium. When the water these fishes are living in feature increased levels of nitrate, nitrite, and ammonia will make the fish eyes to come cloudy.

This condition is worsened when there are also increased levels of chloramine and chlorine, too much salt, pH shock, medications, temperature changes, and high TDS levels. This causes the immune system of the fishes to be vulnerable for any and all forms of diseases.

If this is the case you should use an anti parasite treatment which you can get on amazon

Bacterial Infection.

The bacterial infection is also another cause of cloudy eyes for most freshwater fishes. This is usually a result of the infrequency in changing the water in the tank.

It should be noted that white eyes in older fishes may be cataract and occurs as a result of old age. But if you notice whiteness in the pupils of the younger fishes in your tank, it is definitely the cloudy eyes condition.


When fishes are not properly fed, their systems will not receive the necessary nutrient, giving rise to dietary deficiency. This leaves the fishes exposed to a number of harmful diseases—including cloudy eyes.

If you notice in your aquarium, it could mean you’re aren’t feeding the fishes well enough.

These are some common causes of white eyes in fishes. Early detection is key in giving your fish a shot at survival, and a treatment that will be successful.

How do you treat cloudy eyes in fish?

Carry out nitrogen cycles frequently.

Nitrogen cycles are essential in keeping the ammonia level in the tank as low as possible. They also neutralize the toxins, converting it to harmless substances and reducing bacteria inside the tank.

Nitrogen cycles are to be carried out when the tank is emptied of fish. You can follow these simple steps below.

  • Pour chlorinated freshwater into the empty tank
  • Spray pieces of flake foods daily in the water till you discover an increase in ammonia
  • Continue to put food into the tank until you can detect an increase in nitrites. By then, the ammonia level will be reduced somewhat. As the ammonia and nitrite levels decrease, nitrate will start appearing inside the pond.
  • The nitrogen cycle has been completed when the ammonia and nitrite levels are at 0 ppm.

Change the water regularly

Since poor water quality is a major reason for whiteness of eyes, you owe your fish the responsibility of changing their water regularly.

Frequent water changes will keep the pond clean, crystal clear and oxygen-abundant for the fishes to stay healthy.

Carry out regular cleaning

As you change the water in the tank, ensure you’re also cleaning it to good condition. You can use a gravel vacuum to clean out toxins including rotten feces and food stuck in the tank.

You can also take out the ornaments and other decoration and give them a smooth shine before putting them in place.

Be mindful of medication overdose

If you’re applying medication to the fish through water immersion, be careful not overdose. Medications such as formalin in high doses can cause cloudy eyes.

Feed your fishes properly

Another way to treat this condition to properly give your fishes the required nutrient and vitamins-filled food.

You can spice things up by adding live foods like mosquito larvae, bloodworms, and daphnia once a week. You should ensure that you’re getting the best pellets for your fish to feast on.

Get a good filtering system

It is important to get an efficient filtering system for your aquarium. This filtering system features mechanical, biological and chemical functions.

While the mechanical filter removes debris, the biological filter sucks up biological waste while the chemical filter gets rid of harmful chemical substances.

Also, you should change your filter cartridges when and if necessary.


Taking care of the fishes in our aquariums should be a priority. It is therefore important to carry regular close-up checks on the fishes to easily spot the cloudy eyes condition and do the needful before it gets out of hand.

The aforementioned control measures will guide you on what to do should such conditions arise or if you’re currently experiencing it.

Meta description: This article explores all you need to know about the causes of cloudy eyes in fishes and how to prevent and treat such occurrences.