Can Betta Fish See in The Dark? Truth of Betta Eyesight

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It’s usually a good idea to do proper research before getting any pet. Your research must cover everything like body structure, temperament, dietary needs, common diseases, and more.

Learning the basic needs, behavior, and genetics will always allow you to deliver the utmost care. As you know, betta fish need good eyesight, but how does having poor vision impacts their health and surroundings?

Can Betta Fish See in The Dark

Bettas need their eyesight more than other sensory organs in order to survive and catch their prey in nature.

As a result, they have developed quite powerful eyesight that can see a lot better than us. However, there are a few drawbacks to betta eyesight.

Let’s understand how the betta eye works, how daylight and night affect their vision, how much sunlight is safe for them, and much more.

How Is the Betta Eye Different from The Human Eye?

Excellent vision is essential for every wild species as it keeps them alive and strong. It is especially the case for species such as betta since they are carnivores who hunt by their sensory receptors.

It indicates that betta use eyesight to search for food in their natural habitat. Its eyesight provides an opportunity for it to hunt. Bettas won’t be able to consume if they can’t detect their target.

Bettas have monocular sight because their retinas include rods. It indicates that they have a wider visual area, and both their eyes can simultaneously look in opposite directions. It is not possible in the human eye as we have binocular vision.

But, bettas struggle to focus both of their eyes towards a single object.

Do Bettas Have Different Eye Shapes and Vision Abilities?

The pupil of many tropical mammal eyes, including those of humans, could shrink and refocus (usually as people look very closely,) whereas the pupil of betta fishes remains fixed in one position and can not autofocus.

Because of their weak spatial vision, betta fish primarily rely on sunlight to assist them in identifying their surroundings and finding food. Bettas need artificial lights if there is no source of sunlight in their surroundings in order to fulfill their basic needs.

The cornea of nocturnal animals has changed with evolution to utilize more rods than photoreceptors for color perception and the detection of colorful LEDs.

It is understandable for these species as they are always more energetic during the daylight hours than in dark.

Although their monocular eyesight could make it difficult for them to notice things and prey from far away, their capability to differentiate hues is way better than humans.

The Role of Iris and Lighting

The iris regulates the amount of sunlight that reaches the eyes. A betta’s retina cannot effectively adapt to changes in light exposure, in contrast to mammalian binocular sight. It’s possible to describe the betta fish’s cornea activity as weak.

Due to the weak retinal performance, the pupil cannot immediately adapt to fluctuations in bright light or pigment, and the species would probably get startled whenever there is a rapid change in light in their surroundings.

To minimize unwanted stress and danger to your freshwater fish, limit dramatically strong lighting or excessive light sources in a single place.

However, this species’ monocular eyesight does not assist them in determining spatial vision. You may think that your fish would run into things in its aquarium because it has a poor spatial vision. Interestingly, it never clashes with anything.

Bettas have developed a different way of identifying and exploring their environment, similar to the majority of species. Fish have what is known as horizontal streaks, which are a collection of small openings that serve as pressure receptors across their body.

This horizontal streak detects fluctuations in hydraulic pressure surrounding their body and considerably supports sensory system weaknesses like poor retina functioning or non-chromatic perception.

A pressure signal is created whenever anything travels across water, like the bug embryos that the exotic betta enjoys.

The horizontal streak detects changes in hydraulic pressure and provides a broad idea of the entity’s position in relation to the species, similar to the echolocation process in dolphins.

Can Bettas See in The Dark?

The primary factor contributing to betta’s weak night vision is how badly their iris functions. The iris of every eye has overall control over the amount of light it receives.

A larger iris allows additional light to enter. Unfortunately, betta has a tiny iris, so you can not expect bright light to enter their delicate eyes.

The iris works incredibly slowly for these species to allow light into their eyes for better vision. Therefore, they struggle a lot when you shut down their aquarium lights, as their iris can not adjust quickly, resulting in blurred vision.

It causes them to go blind for a few minutes, which is frustrating and scary for these species.

When the lighting starts changing, it ends up taking the betta’s eye almost equivalent time as it does for the sun to disappear (approximately 30 to 60 minutes).

Planting your aquarium extensively is one approach to provide your betta with a stress-free, secure habitat to enjoy both shade and sunlight. Your fish can benefit from diffused sunlight from various planting regions in the aquarium, which will improve its vision.

Additionally, it would help your betta’s iris to adapt effectively to extremely bright light without harming or impairing its vision.

Do Betta Fish Need Darkness While Sleeping?

Bettas prefer snoozing at night since dozing odd during the daylight is problematic for these species. They would spend the entire day scavenging for nutrition and wandering inside its aquarium.

Whenever there is darkness all around their tank, bettas get an idea that it’s their time to rest. Bettas release the pent-up energy they accumulate when resting during the night.

Bettas would probably snooze off if you shut down all the aquarium lights as well as their surrounding light sources, as these species find it comforting in darkness. A betta knows when it has to go searching and exploring for food during the day and when it may unwind and rest during the night.

Even if your pet fish doze off sometimes in the daytime, it receives better sleep during the night without any interruptions.

In order to give your pet the greatest possible sleep, you must keep the aquarium lights off. Giving your betta the greatest sleep can help prevent it from feeling anxious or uncomfortable.

Can Betta Fish Eat in The Dark?

Being a non-nocturnal freshwater fish, bettas prefer to stay inactive during the night as they haven’t gained the ability to see clearly in darkness.

Although bettas are capable of detecting items and feeling them nearby using their horizontal streaks, they find it difficult in seeing them in the dark. Therefore, it is advised to feed your fish only in the daytime or with proper aquarium lights as can’t see their food in the dark.

Although bettas have receptors to stop them from running into something hazardous, the efficiency of these receptors continues to be in question when it is about seeing minute food particles.

Therefore, these species always need light to find their prey in the wild or food in captivity. Don’t worry if your betta has not finished its feed at night.

Also, they certainly do not require aquarium lights on when they sleep. Let these creatures sleep in complete darkness even if you see them awake in the middle of the night.

The Betta Iris Functionality in A Day vs Night

When you house your betta fish in light to moderate sunlight or artificial light during the day, it can stay healthy and energetic all day long.

Whereas, if there is no light, then they consider it as sleeping time in their native environment. As a result, napping is important for them to completely recover and restore their energy.

The optimum amount of sunlight for a betta is ten hours daily. Sunlight offers significant perks in supporting the body’s functions and basic activities.

Therefore, it is essential to give them enough sunlight for their development. However, you should not leave your fish in a dim setting beyond ten hours. They’ll face serious health consequences if you maintain them in a dim area for a long time.

Some people also claim that betta fish require a minimal source of light during the night. They believe that having complete darkness can affect their activity level.

However, many researchers reveal that housing them in the darkness poses no such harm. It has been always the topic of debate that bettas have a positive effect on their sleep and healthy when kept in darkness during the night, as compared to a setting with proper lights.

Nonetheless, more research is currently undergoing to determine the extent to which darkness affects their development. However, it has been shown that these species do not have excellent night vision to detect their food.

What Colors Can Betta Fish See?

Betta species can never have an excellent spacial or distant vision as a human eye. However, they are able to get a unique exposure and intensity of colors far better than us in daylight.

According to some research, bettas have the same visual spectrum as the human eye, which includes over 300 hues as well as the ability to distinguish between infrared colors.

But, deep down the sea, they can only see colors that have a specific wavelength. For instance, red tones possess a higher wavelength as compared to blue and green.

Those having higher wavelength travels and spreads in the sea significantly faster and deeper than other tones with shorter wavelengths. It means that bettas might not always see red color.

What Happens if Your Betta Eye Gets Excessive Light?

You are aware that bettas are more energetic during daylight hours or under artificial light. Overexposure to sunshine or other bright lights could make your pet restless and stressed out, which might result in difficulties in eating.

Additionally, extended duration of sunlight or excessive UV rays can increase the water temperature to a certain degree that could be extremely hot for bettas. The elevated temperature can change the water properties and make your fish violent.

As a result, it is strongly advised from keeping the aquarium in direct sun for an extended period of time. It is best to use artificial lights instead of bright UV rays.

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Do Bettas Require Light?

Yes, bettas require sufficient light just like they get in their native home. Natural or artificial light is very important for these species to maintain their health and sleeping schedule.

How Many Hours Does Betta Need Light?

These species require a minimum of 8 to 10 hours of light. You must try not to exceed the light hours by more than 12 hours, as it could disrupt their routine.

Do Bettas Tolerate Led Lights?

Bettas have no problems with LED light as long as you meet their daily light hours. However, the lights should not be overpowering for their weak iris functionality.


Bettas are complex animals that rely on their sensory organs to thrive. Even though they have the ability to see a bit at night, they usually depend on their natural instincts and horizontal streaks.

They enjoy daylight hours the most as they could hunt and wander inside their tank with complete freedom.

It’s important for your betta fish to sleep peacefully. Maintaining a proper balance of day and night hours is important to keep them healthy in the long run.

Therefore, don’t leave the tank lights on for an extended amount of time when they are sleeping.

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