blue betta in tank

Can Betta Fish See In The Dark?

So, can your betta fish see in the dark? The short answer is no, as they require light to see properly. But that’s not the whole story.

Understanding how betta fish see can be your ticket to understanding how exactly they function during the day and at night, both of which are vital to their overall health. Giving your betta the ideal lighting conditions at specific times of the day ensures it has healthy sleeping patterns and that its aquarium mimics its natural living habitat.

Read on to learn more about betta fish vision, how they perceive colors and shapes, and tips on providing the ideal lighting conditions for your pet fish.

How Betta Fish Vision Works

Betta fish have monocular sight. This means their retinas include rods which gives them a wider visual area and means each eye can simultaneously look in opposite directions. 

Unlike humans, bettas struggle to focus both of their eyes on a single object. Their capability to differentiate hues is better than humans, although their monocular eyesight makes it hard for them to see things from far away.

Betta fish eyes include different components, including the iris, retina, and cornea. The iris controls the amount of sunlight that reaches the eyes, and the retina contains rods that allow betta fish to detect light and distinguish colors. The iris of betta fish works slowly, so they struggle to see in low-light conditions. They primarily rely on sunlight to identify their surroundings and find food, and they require artificial lights if there’s no source of natural light in their surroundings to fulfill their basic needs.

Betta fish can’t see in the dark, as they have a small iris, which doesn’t allow enough light to enter their eyes. Factors like water clarity, the presence of artificial light, and their natural adaptation to low-light conditions can affect their vision in these environments.

What Type of Lighting Is Best for Betta Fish?

The best lighting conditions for betta fish are low to moderate light, simulating their natural environment.

Avoid direct sunlight, as it can increase the water temperature, encourage algae growth, and cause stress for the fish. Artificial lighting can help create a natural day and night cycle for your betta fish, with a period of darkness essential for their sleep cycle.

Betta fish can see various colors, including blue, green, and yellow. However, they can’t see as many colors as humans. Certain tank decorations, like LED light ornaments, can help bettas perceive light better.

Floating plants can also provide shade and reduce the amount of light entering the tank. Some of the best lighting options include:

LED Aquarium Light

LED lights are a popular option for betta fish tanks because they are energy-efficient and long-lasting. They also produce minimal heat, which can help regulate the water temperature in the tank.

This LED Aquarium Light by NICREW has adjustable brightness levels and can be customized to different color settings.

Full Spectrum Aquarium Light

Full spectrum lights provide a range of light wavelengths that mimic natural sunlight. As a result, they can promote plant growth and enhance the colors of fish.

This Hygger Full Spectrum Aquarium Light is adjustable and has a remote control.

Smart Aquarium Light

Smart lights allow you to control your tank lighting from your phone or other devices. They often have features like customizable lighting schedules and special effects.

This Fluval Aquasky LED Aquarium Light can be controlled via the FluvalSmart app and has multiple color options.

How to Optimize Your Betta’s Sleep With Lighting Conditions 

In their natural habitat, bettas rely on the presence or absence of sunlight to indicate when they should be active or sleeping. Therefore, providing a calm and dark environment for them to fall asleep is essential to maintain their natural sleeping schedule.

Bettas require about eight to ten hours of sleep during the night to support their natural processes and be active during the day. Too much light can disrupt their sleep cycle and cause them to stay awake longer, leading to exhaustion and stress.

The ideal scenario is to provide adequate lighting during the day to simulate an appropriate daytime for the fish to be active and turn off the lights at night to create a sense of calm and rest. A relatively dark room can make it challenging for bettas to determine whether to rest or be active, so providing enough light to distinguish colors during the day is essential.

How to Optimize Your Betta’s Vision

Optimizing your betta’s vision is crucial to maintaining their eye health. One pro tip is to avoid exposing them to bright and sudden light, which causes stress and harms their eyesight. Here are some other tips to optimize your betta’s vision in the dark;

Use a Dimmer Switch for Your Aquarium Light

Betta fish need a balance between light and darkness to regulate their sleep cycle and distinguish between day and night. Installing a dimmer switch for your aquarium light can help you control the amount of light your betta receives, allowing you to simulate a natural environment and promote healthy vision.

Use Moonlight or Night Vision Lights

Regular aquarium lights can be too bright for your betta fish to see correctly in the dark. Instead, use moonlight or night vision lights, which emit a low-level, blue light that mimics the natural moonlight and is more comfortable for your betta to see at night.

Avoid Sudden Changes in Light

Sudden changes in light can startle and stress out your betta fish, potentially leading to health problems. If you need to turn on a light at night, gradually give your betta time to adjust.

Does Water Quality Affect Betta Vision?

Poor water quality can have a significant impact on betta fish’s vision. When the water quality isn’t maintained correctly, harmful toxins and chemicals can accumulate, leading to bacterial and fungal infections that can cause eye diseases. These diseases can result in cloudy or swollen eyes, difficulty seeing or locating food, and even blindness.

Poor water quality can also cause algae growth, clouding the water and reducing the amount of light penetrating the tank. That can make it difficult for betta fish to see and distinguish objects, colors, and movement, leading to stress and disorientation.

Here are some tips to keep your tank clean and maintain water quality to promote healthy eyesight for your betta fish:

  • Regular water changes: The most effective way to maintain water quality and tank cleanliness is to perform routine water changes. Change 25 to 30 percent of the water weekly, and ensure you run tap water through a water conditioner to remove any heavy metals.
  • Proper filtration: A filtration system is necessary to keep aquarium water clean and clear of debris and waste. Choose a filter suitable for your tank’s size and replace the filter media regularly as recommended by the manufacturer.
  • Avoid overfeeding: Overfeeding your betta fish can lead to excess waste, uneaten food, and poor water quality. Instead, feed your Betta small amounts of food 2-3 times a day and remove any uneaten food after a few minutes.
  • Remove uneaten food and debris: In addition to overfeeding, uneaten food and debris can accumulate on the bottom of the tank and contribute to poor water quality. Use a siphon to remove any waste and debris from the substrate during water changes.
  • Monitor water parameters: Regularly test the water parameters in your tank to ensure that they are within the appropriate range for betta fish. The ideal temperature for betta fish is between 76-82°F, the pH should be 6.5-7.5, and the ammonia and nitrite levels should be at 0 ppm.

🐠Our ultimate guide to aquarium maintenance will teach you everything you need to know about keeping your betta fish’s home clean and suitable to thrive in.

How Can I Prevent Eye Infections in My Betta Fish?

You can prevent eye diseases and infections in betta fish by taking a few simple steps. In addition to maintaining water quality, here are some things you can do to help keep your betta’s eyes healthy:

  • Avoid crowded tanks: Overcrowding the tank can lead to poor water quality, stress, and fighting between bettas. That can increase the risk of eye diseases, infections, and other health problems.
  • Quarantine new fish: When introducing new fish to the tank, it’s necessary to quarantine them first to ensure they are free of diseases and infections that could spread to your betta fish.
  • Observe your betta fish: Keep a close eye on your betta fish and regularly monitor their behavior and health. That helps you catch eye problems early on and prevent them from becoming more serious.
  • Treat infections promptly: If you notice any signs of eye infections or diseases, such as cloudiness, redness, swelling, or discharge, it’s vital to seek treatment promptly. You can consult a veterinarian or a knowledgeable aquarium store for treatment options.

🐠Popeye is a common eye disease for betta fish. Learn how to prevent and treat popeye.

How do I Know if my Betta Fish has a Vision Problem?

If your betta has a vision problem, it’ll hardly go unnoticed. The symptoms are extremely noticeable and you can easily tell by paying close attention.

Here are a few tell-tale signs of a visually impaired betta fish:

Cloudy Eyes

If your betta fish’s eyes appear cloudy or hazy, it could be a sign of a bacterial or fungal infection.

Bulging Eyes

Bulging or protruding eyes can indicate dropsy or a tumor, which can cause vision problems.


 If your betta fish’s eyes are not the same color or appear to change, it could indicate an infection or disease.


If your betta fish is swimming into objects or not responding to movement around the tank, it could be a sign of blindness.

How to Address Vision Problems in Betta Fish

Vision issues in bettas are usually a result of fungal and bacterial infections, which can cause cloudy or hazy eyes, or dropsy,  which causes fluid buildup in the eyes. Tumors can also lead to bulging eyes and other vision problems. Poor water quality, bacterial infections, and genetics usually cause these issues and can be addressed with the following tips.

  • Clean the tank water regularly and remove food residue to lower the chances of bacterial and fungal infections.
  • Use recommended antibiotics like Melafix and antifungal medications to treat infections once identified.
  • Isolate infected fish to prevent the spread of infection to other fish and reduce stress on the infected fish so that it can heal.
  •  Surgery may sometimes be necessary to remove tumors or other growths causing vision problems. Also, ensure you regularly visit your vet, especially when you notice a symptom.

Can My Betta Fish Eat in The Dark?

Feeding your betta fish at night may disrupt their sleep cycle and lead to overfeeding or uneaten food, which can pollute the water and harm their health. Additionally, betta fish have more difficulty seeing in the dark, making it harder to find and eat their food.

Betta fish are naturally diurnal, which means they are active during the day and sleep at night. Their vision is optimized for daylight conditions, meaning they can easily locate and consume food during the daytime but may have difficulty doing so in the dark. It also aligns with their natural feeding patterns in the wild, where they hunt for food during the day and rest at night.

Can Betta Fish See in Complete Darkness?

Betta fish can see in complete darkness, but their vision will be extremely poor. Aside from leaving them practically blind, total darkness can make your betta fish extremely irritated.

Betta Vision Demystified

In this article, we’ve explored the question of whether betta fish can see in the dark. While bettas do have excellent vision during the day, their sight is limited in the dark. Therefore, providing the best lighting conditions for your betta fish is essential to promote healthy eyesight. Did you enjoy this article? Please share your thoughts in the comments below, and don’t forget to share with other betta fish owners.

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