3 Goldfish Eye Problems – Causes & Treatments

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Most species of fancy goldfish have large eyes and even larger fins and tails which are the natural result of selective breeding. Humans have bred goldfish to obtain those characteristics purely because they look good. Unfortunately, the same features are often the subject of injuries and infections, putting the fish’s life at risk.

Goldfish are notorious for developing eye problems, mostly due to improperly decorated tanks. Everybody likes to aquascape their tanks and add in enormous decorations, which could work with other fish, but don’t with goldfish. The latter are more sensitive and can experience cuts, eye punctures, and fin tears due to rubbing against rugged or sharp edges and even the side of artificial plants.

Combine this issue with suboptimal water parameters, and infections are guaranteed. But what are the most common goldfish eye problems, and how can you diagnose and treat them correctly? Here are the most widespread conditions:

Popeye Disease

This is a common eye conditions in goldfish due to their sensitivity to poor water parameters and being more prone to injuries. Popeye disease isn’t a disease in and of itself, but rather a symptom stemming from underlying problems that could aggravate with times. If left untreated, this eye condition could lead to the goldfish losing one or both of its eyes.

This isn’t necessarily a life-or-death matter since the goldfish can live long and healthy lives even after losing both of its eyes. The real problem is the risk of additional complications and secondary infections that could cost your goldfish its life. So, before anything else, diagnosing the condition accurately and as fast as possible is key to a more effective treatment.

Symptoms of Popeye Disease

The earliest sign of Popeye disease is the distinct swelling in one or both eyes. The fish’s eyes will appear to protrude in an aggressive manner, informing you that something’s not right. As the disorder progresses, other symptoms may appear soon, including:

  • Stretching in the eye socket along with bloodshot eyes and inflamed eye tissue
  • Cloudiness or ruptured eyeballs in more severe cases
  • Swelling around the fish’s head and body
  • Behavioral changes, including unusual hiding, refusing food and displaying unexplained lethargy

The idea is to identify these problems as early as possible to stop the disorder’s progression and minimize the damages. The treatment will vastly depend on the condition’s causes since there are several to account for.

Causes of Popeye Disease

There are 3 main causes responsible for Popeye disease, including:

  1. Physical injuries – These may occur due to the goldfish bumping into various plants and tank decorations and even fighting with other goldfish or tank mates. This doesn’t generally happen because goldfish are peaceful creatures, but they can also be territorial at times. And, in most situations, they can get bullied by more aggressive tank mates. Their eye injuries can get infected fast, potentially leaving them blind or even leading to even more dangerous infections.
  2. Parasites or bacteria – While goldfish are rather hardy and won’t get sick easily, they also display an increased sensitivity to environmental bacteria, fungi, and parasites. Especially goldfish with compromised immune systems due to poor water conditions, genetic faults, old age, or other diseases. If a pathogen is responsible for your goldfish’s eye problems, you should detect the tale-telling symptoms ahead of time. These include lack of appetite, aggressiveness, hiding behavior, color changes, skin growths, etc., depending on the nature of the pathogen.
  3. Improper water conditions – Your goldfish require stable water parameters, otherwise, they will experience discomfort, depending on how severe the situation is. The most affected fish are those with compromised immune systems, leaving them more vulnerable to ammonia, nitrites, and dirty water.

As you can see, diagnosing the disorder quickly and accurately allows you to apply the right treatment to ensure your fish experiences a fast recovery. Even so, the situation may advance so fast in some cases that the goldfish will lose an eye or both of them. This isn’t much of a problem since your goldfish can live a healthy life even without its sight, provided it doesn’t face secondary infections or complications along the way.

How to Treat Popeye Disease?

The treatment depends very much on the condition’s triggering factors. If you notice changes in your goldfish’s eye color, size, or shape, proceed as follows:

  • Quarantine the fish – This may not seem necessary for such minor symptoms, but it is. You still don’t know what you’re dealing with. If it’s a parasitic or bacterial infection, you want to protect the other fish and prevent the pathogens from spreading, so quarantine is necessary. Make sure the conditions in the treatment tank mimic those in the main one to prevent fish stress.
  • Ensure optimal water parameters – You may need to change the water every other day or even daily, depending on how small the treatment tank is and how severe the fish’s symptoms are. Change around 15-20% of the water each time. Any more than that could dilute the essential minerals in the water, which will stress out your goldfish. You should also rely on a heater to maintain temperature stability, clean fish droppings, and remove food leftovers to prevent the formation of ammonia and nitrites.
  • Use medication if necessary – You may need to rely on various antibiotics and other medications if your fish shows signs of parasites or bacterial infections. Just make sure you diagnose the goldfish’s condition accurately, and you use the medication as prescribed. You can even speak to a veterinarian to make sure you perform the treatment safely.
  • Allow your fish time to recover – Sometimes, you may not even need to use any medication at all. If it’s a rather banal injury, all your goldfish needs are time to recover, a nutritious diet, and pristine water conditions. I also suggest monitoring your goldfish during the recovery phase to make sure everything’s progressing to plan.

If you detect Popeye’s disease in time and act before it aggravates, the chances of complete recovery will increase dramatically.


Cataracts is a common condition in fish, as well as most other animals, humans included. The disease is progressive, and you can typically notice its symptoms aggravating with time. Fortunately, cataracts isn’t necessarily a severe condition, except when it aggravates to the point where the goldfish won’t be able to see anymore. But it won’t affect the fish in any other meaningful way.

Even so, diagnosing the condition earlier can allow you to address it before it advances.

Symptoms of Cataracts

The most obvious symptom is the cloudy eye lens. It may seem innocuous at first, but as the disorder progresses, the eye’s lens will become opaque. As a result, your fish won’t be able to see as well, appearing disoriented at times. With time, blindness is the natural outcome, at which point the eye will appear milky white.

Other than that, the fish will display no other symptoms since cataracts is nothing more than a thickening and whitening of the lens fibers. In case of injuries, the same effect occurs in the surrounding tissue that encapsulates the eye’s retina. The disorder will remain localized, with the victim exhibiting no other symptoms other than those visible in the eyes.

Causes of Cataracts

Unfortunately, there are multiple reasons behind the formation of cataracts, including:

  • Drastic exposure to UV lighting – This places goldfish in a specific risk category since they don’t naturally require high levels of UV lighting compared to other fish. Wild goldfish live in murky and muddy waters and will only receive minimum amounts of sunlight throughout the day. Exposing them to direct intense sunlight for long periods or subjecting them to extreme artificial UV lighting will directly impact their eyesight.
  • Genetic susceptibility – This is one factor that you cannot control, especially when it comes to fancy goldfish. These are the product of thousands of years of human genetic manipulation, which comes with increased risks of genetic faults. Some fish display a genetic predisposition towards specific diseases, including cataracts. There’s no way of telling which fish are more predisposed to this condition unless you backtrack their genetic tree. Which isn’t worth the effort anyway since cataracts isn’t that serious, to begin with.
  • Nutritional – This is a crucial point since goldfish are omnivorous and require a carefully-planned diet. Vitamin and mineral deficiencies are common in poorly fed goldfish, which can have dire consequences long-term. It turns out that goldfish can develop a multitude of health issues, including cataracts, due to their diets lacking thiamine, manganese, zinc, riboflavin, tryptophan, etc. I suggest informing yourself on goldfish’s dietary needs before planning their meals.
  • Flukes – This is a common parasite that can affect goldfish’s eyes, body, or gills, causing a variety of symptoms, both physical and behavioral. Your fish may rub against hard surfaces constantly, display red patches on the skin and mucus covering the body or gills. The same parasite may also cause cataracts when infecting the fish’s eyes and will kill the host if treatment isn’t available soon.

Other potential causes include gas supersaturation, dangerous fluctuations in water salinity and environmental toxins, extreme side-effects from various drugs, etc.

How to Treat Cataracts?

The only treatment available is surgical. The technique used is called phacoemulsification and relies on sound waves to dislodge the cataracts and vacuum the leftovers. The treatment’s success depends on the fish’s age, recovery capabilities, and how severe the condition is. If your goldfish shows signs of age-related cataracts, the treatment may not be as effective.

Either way, you should contact a fish specialist if your goldfish shows cloudy eyes. The treatment may be successful if the disorder is in its incipient phases.

Cloudy Eyes

This isn’t a condition but rather a symptom of several potential conditions. Including cataracts, which we’ve already been through. It’s important to note whether your goldfish displays additional abnormal symptoms, aside from the cloudy eye lens. This can help you diagnose the fish’s condition accurately and set up the adequate treatment for a smooth recovery process.

Symptoms of Cloudy Eyes

The eyes get cloudy. This is the most relevant symptom showing that there’s something affecting the fish’s eyesight, but you can’t rely on this sign alone to diagnose the condition. You need additional information for that, and you will only get that from assessing any additional signs your goldfish may display. These may include:

  • Diminished appetite or refusal to eat
  • White growth on the eye lens or around the eyes or mouth
  • Color changes and the presence of red patches on the skin
  • Bloodshot eyeballs
  • The tendency to hide or swim near the substrate, etc.

Depending on the symptoms, the goldfish may require immediate treatment in a separate environment, especially if the condition is contagious.

Causes of Cloudy Eyes

Your goldfish may display cloudy vision for a variety of reasons, some of which are more severe than others. These include:

  • Injuries – It is one of the most widespread causes, especially among large-eyed goldfish like the telescopic fish, black moor, and others. The incidents tend to occur primarily in heavily decorated tanks or when pairing the goldfish with inquisitive and aggressive fish species that tend to bully their tank mates. The problem with injuries is that they can get infected fast, especially if the water quality isn’t exactly pristine.
  • Improper dieting – Many people tend to ignore their goldfish’s diet and will only feed them one type of food. This could lead to vitamin and mineral deficiencies that might affect their health in the long-term. Vitamin A deficiency is pretty relevant in this sense since this vitamin is essential for your goldfish’s eye health.
  • Parasitic infections – We include the flukes here, which are tiny parasitic worms infecting the fish and feeding off of its tissue. This worm is a viral organism capable of spreading to other goldfish and tank inhabitants and will display a variety of symptoms. One of them is the cloudiness in the goldfish’s eyes. If ignored, the parasite can cause blindness and even lead to the death of its host.
  • Localized infections – These are common in goldfish with compromised immune systems that live in questionable conditions. If the water is unclean and the fish’s environment is dirty, the risk of contracting an eye infection is greater, especially for fancy goldfish. The infection’s type and severity depend on the causing agent, whether it’s fungal, parasitic, or bacterial. You should assess the situation and symptoms carefully to determine the right treatment approach.
  • Genetics – We’re not talking about genetic disorders but rather inherited characteristic. Some species of goldfish will simply develop cloudy eyes, which are nothing more than an esthetic feature. It doesn’t affect their vision, and it’s not a symptom of any health problem. So, nothing to worry about.

How to Treat Cloudy Eyes in Goldfish?

First, you need to determine the cause. After that, it all comes down to addressing the issue in a controlled and hygienic environment. In this sense, you have several treatment procedures available, depending on the nature of the disorder:

  • Adjust water parameters – Goldfish may experience cloudy eyes due to unhealthy ammonia levels in the tank. By ‘unhealthy’, I mean anything above 0. If your tank shows ammonia levels well above 0, the fish’s cloudy eyes will be the last of your concerns. Ammonia is poisoning fish and will affect their behavior and bodies even in small amounts. You should also verify the water for any chlorine or chloramines that may have leaked into your tank one way or the other.
  • Medication-related effects – If you’ve used the main tank as a treatment environment for some fish and mixed medications in the tank water, you might want to look into that. Some medication can affect your goldfish’s eyes, especially in larger-than-normal quantities. I suggest performing several water changes more often than usual to dilute the drugs and rebalance the environment. You might want to move your fish into a temporary tank in the meantime.
  • Quarantine and antibiotics – This phase is necessary if you’ve determined that your goldfish has a parasitic or a bacterial infection affecting their sight. At this point, you should move the sick fish into a treatment tank and use antibiotics to eliminate the pathogens. You should also keep the fish’s water at optimal parameters and increase the water’s temperature slightly to accelerate the pathogen’s life cycle.
  • More specialized treatments – These include ultrasound or surgical interventions in case your goldfish has cataracts or any other condition that requires a professional’s assistance. If you can’t figure out the disorder’s type and triggering factors, I suggest speaking to a vet for expert support.

In essence, your goldfish should recover fast with early and adequate treatment, provided the fish is young, healthy, and strong.


The cloudy eyes syndrome isn’t much of a disease in and of itself but a symptom. There may be numerous underlying conditions or triggers responsible for the goldfish’s cloudy eyes, and diagnosing them accurately and fast is key for a smooth recovery process.

Fortunately, goldfish are tough, so they should be able to make a full recovery with adequate assistance and provided the nature of their condition allows it.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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