Can Betta Fish Go Blind

Can Betta Fish Go Blind?

While most people know that fish can become sick from fungus or bacteria, a fish going blind doesn’t cross every fish keeper’s mind. How would you even go about caring for a blind fish? What are some of the major obstacles? And, most importantly, can they go blind, and if so, how?

Betta fish can become blind due to a variety of reasons, most notably dragon eye, cataracts, fungal infections, bacterial infections, parasitic infections, and trauma to the eye. Caring for a blind, or visually impaired, fish is different from caring for a fish with good eyesight. Fish have a much harder time finding food if they cannot see it, and betta fish are sight predators and greatly rely on their eyesight. Fortunately, betta fish are also incredibly smart and have a great memory, so it very possible to train your blind fish to live normally.

In this article, we will cover dragon eye, cataracts, infections, losing an eye, and caring for a blind betta fish.

Dragon Eye

Dragon eye, also known as diamond eye and snake eye, is a rare condition that primarily occurs in bettas with altered scales, normally dragon scales. Bettas with dragon scales have been selectively bred for unusually gorgeous, thick, and vibrantly colored scales. While this is one of the most beautiful scale types, this is also the one with the highest rate of dragon eye, hence the common nickname for this illness.

Dragon eye occurs when the scales of a betta begin to grow abnormally over the eye. They start out as nearly translucent, though somewhat visible, tiny scales in the eye. Not all owners notice this first stage, as it can be easy to miss. Therefore, it is important to frequently monitor the health of a dragon scale betta’s eyes.

The scales will soon start to grow in number, become colored, and increase in thickness. In a matter of weeks, they can completely cover the eye. In addition, dragon eye normally occurs in both eyes at about the same time.

The exact cause of this illness is unknown, though may owners report a previous eye infection of some sort before dragon eye set in. This points towards the theory that dragon eye is an abnormal immune response; the body tries to get rid of an infection of some kind, goes haywire, and starts growing scales in areas that scales should not be growing.

While this has not been proven or backed by any research, I have not had dragon eye that occurs in any of my bettas that never had an eye infection. I have had it occur in just a single one of my bettas, about two weeks after clearing an eye infection.


As bettas and other organisms age, their bodies undergo changes, most of which end up making life more difficult. For example, betta fish can develop cataracts due to old age, which is clouding the lens of the eye. This prevents light from entering the eye correctly, which makes it very difficult, or even impossible, to see.

While humans can get highly successful surgery to correct this, the same cannot be done for bettas. Betta fish are very small creatures, so small that the tiny bit of chlorine in normal water will poison them, and so small that unfortunately, surgery is not normally possible.

While there are a few major surgeries that have been done successfully, surgeries that deal with a small area of the betta, such as the eye, or even a tumor, cannot be done. Even the larger surgeries have low success rates, simply due to how small a betta is.


Infections in fish are not at all uncommon, as our tap water is filled with pathogens that can affect them. A healthy fish will be able to fight these off normally, but sometimes we can accidentally introduce illness into our aquariums, or their immune systems will become weak, which leaves them open to infection.

A weakening immune system can be caused by specific medications (if you happen to be medicating your fish for an unrelated illness, or simple quarantine policy), an unhealthy or unbalanced diet, stress from loud noises, lights, seeing their own reflections, and a whole host of other possible reasons. It can happen frequently, and every fish keeper should expect to deal with an illness at some point.

Luckily, illnesses dealing with the eyes (aside from pop-eye) are uncommon in betta fish. While you will experience some sort of illness at some point, it will likely not deal with the eyes. However, due to the possibility of severe negative health impacts that can occur from an eye infection, you should be prepared to handle them.

The first sign that something is wrong with your betta’s eye is normally a slight clouding of the lenses. Cataracts will present the same way, but they typically only occur in bettas 3-4 years and older, and are gradual cloudiness over a period of weeks or months. An infection will spring up seemingly overnight and become drastically worse over a few days to a few weeks.

The issue with eye infections is that they can be parasitic, fungal, or bacterial, and the odds are seemingly equal. It is best to treat the tank with some kind of general “cure-all” medication that can handle external parasites, gram-positive and negative bacteria, and fungus.

Losing an Eye (or Two)

While some illnesses, such as pop-eye, can cause one or both of a fish’s eyes to fall out, the normal cause is them getting into a fight with another fish, or running into a decoration. While betta fish are very intelligent creatures, they do have their moments.

If you keep fish for several years, one of them is going to lose an eye at some point. I have had a fish in a tank with no traditional decorations, only soft-leaved plants, somehow lose an eye. The good news is that if they only lose one eye, they will be able to function at almost 100%, and you may not even notice a difference for several days.

Of course, you need to immediately check the tank for any sharp objects, and you may want to consider removing any hard or solid decorations, at least for the time being. If your fish only lost one eye, and you have done your duty to scour the whole tank for the possible offender, your job is nearly done.

Simply do some extra water changes and be extra vigilant about the water parameters. This will decrease the risk of infection to the newly exposed flesh, and lower nitrates will help your fish recover faster. You may also want to consider adding an Indian Almond leaf for its antifungal and antibacterial properties, though be prepared for the color of your water to change.

If your fish lost both of its eyes, it is now entirely blind and should be cared for in the manner laid out below.

Caring for a Blind Betta Fish

The first step in caring for blind fish is making the tank safe for them. They can no longer see sharp, or even blunt, decorations, so it is best to remove as many solid or potentially harmful decorations as possible.

The best thing to do would be to replace them with live plants, though this isn’t possible for everyone. Be sure to have a heater guard on your heater and consider adding a sponge to cover the filter intake.

If your fish became blind suddenly, feeding them may be tricky. It is best to have a particular spot that you feed them in every day. If you already had one, stick to that area and feed the same type of food.

On the other hand, if your betta is slowly going blind, feed them in a specific area of the tank, but start adding in an auditory cue. For example, gently tapping the top of the tank before dropping food in the designated area. Once they go completely blind, not only will they know where to go to get food, but they will also know when to go get food.

A betta’s memory is much longer than most people think, averaging a few months to a few years. This means that they will not soon forget where to get their food, and food is the primary concern with this condition. Once you overcome it, your betta will still be able to happily swim around and nap all day, just like a betta with full sight.

In conclusion, it is possible for a betta to become blind, whether it is from the diamond eye, cataracts, infection, or the physical loss of their eyes. Set the tank up to be safe for a blind fish, feed your fish in the same spot every day, and continue to care for them normally.

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