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Can Betta Fish See In The Dark? Vision Explained & FAQs

Lindsey Stanton Profile Picture

By Lindsey Stanton

betta fish

The betta fish is one of the most beautiful aquarium fish you could get, and although they are a bit territorial and aggressive, they’re a lot of fun to have around. Something you might be interested in knowing is what the vision of betta fish is like. How well do these fish really see

Can betta fish see in the dark? The answer here is that while they can see a little bit in the dark, their night vision is not great due to the poor iris functionality a betta has. If we were to compare it to humans, the ability of a betta fish to see in the dark is worse than our own.

Let’s take a closer look at find out exactly what and how betta fish see.

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Betta Fish Vision

betta fish
Image Credit: Armacus, Shutterstock

So, how good is a betta’s eyesight? And can they see color? Let us explain.

You might have noticed that your betta fish is very active and playful during the daytime when there is lots of light, but not active at all during the night. In fact, betta fish will usually just fall asleep in the dark.

How Good Is Their Eyesight?

When it comes to their eyesight in general, betta fish definitely aren’t like predator birds, or in other words, their eyesight is considered to be relatively weak, just kind of bad actually.

What is interesting to note is that betta fish have what is known as monocular vision, which means that each eye can see a different thing, unlike with humans whose eyes work in tandem to create a single picture. However, even more interesting is that betta fish cannot really see depth very well. This is odd because you would think that being able to see two images at once would help with depth perception, but this is not so. Betta fish have big-time trouble with depth perception.

It is thought that because of this, betta fish have pressure sensors along their sides. They cannot see depth well, but they can feel water pressure, which helps them figure out how close to something they are. So, generally speaking, the eyesight of betta fish is relatively bad.

Can Betta Fish See Color?

Although betta fish may not be able to see very well in general, at least not in terms of depth or distance, their ability to see color is actually very good. Betta fish have what is known as diurnal retinas, which means that their eyes contain more cones than they do rods.

We aren’t going to get into the science here, and by no means are we fish optometrists. However, what we can say is that due to this special type of retina, betta fish can see color very well, perhaps even better than we humans can.

Although being able to identify and differentiate between various colors is something that a betta fish can do very well, they do need a good deal of light to do so. As you’re about to figure out, not only can betta fish not perceive depth and distance very well, but they also can’t see too well in the dark either.

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Betta Sight In The Dark

betta fish in dark
Image Credit: UNIKYLUCKK, Shutterstock

The most important thing to note in relation to this question is that betta fish have fairly poor iris functionality. The iris is the part of the eye that determines how much light is being let in. If the iris is large, more light gets let in, and vice versa. Due to the poor iris functionality of betta fish, they don’t do well when the level of lighting changes quickly. In other words, their irises cannot quickly adjust when lighting quickly increases or decreases.

Even if there is some ambient light in a room, if you turn the aquarium light off altogether in a split second, your betta fish won’t be able to see much, if anything at all, because it takes a long time for their irises to become larger and let more light in. Moreover, this poor iris functionality goes even further than this, because their irises just don’t get all that large to begin with, which means that their eyes only let in so much light even when the irises are at their largest.

Therefore, no, betta fish really cannot see in the dark very well, if at all. How much they can see in the dark is debatable, but nobody is going to claim that they have night vision like cats do.

Do Bettas Like Being in the Dark?

The quick answer here is that no, betta fish do not enjoy being in the dark, at least not during the day, although nighttime is a different story. Just like us humans, when we want to sleep, we want it to be dark. Some people put lights in their betta tank to provide some illumination at night, but this doesn’t make any sense.

How would you feel if there was a light shining in your face while you’re trying to sleep? During the night, these fish have no problem being in the dark, as it helps them sleep. Moreover, that sixth sense, so to speak, which we talked about before (a betta fish’s ability to sense pressure and objects close by), will prevent them from swimming into anything when it is dark.

So, during the day they like it bright, and during the night they like it dark. Makes sense, right?

Can Betta Fish See Their Food in the Dark?

No, a betta fish will not be able to see their food in the dark very well at all. Now, if there is a little bit of light, they may be able to see outlines, but this is debatable. Seeing as betta fish have relatively poor vision, especially when it comes to night vision, the experts are quite sure that they won’t be able to see food in the dark.

Even though they have those pressure sensors to prevent them from swimming into anything, whether or not these sensors are sensitive enough to detect super small pieces of fish food is questionable at best.

Betta fish need light to hunt and to see their food, which is why you’ll never see them eating during the night.

betta fish
Image Credit: Panpilai Paipa, Shutterstock

Can Betta Fish Sleep in the Dark?

Yes, not only can betta fish sleep in the dark, but they actually really need it to sleep. Once again, this is exactly the same as with humans.

We like darkness to sleep and so do betta fish. In fact, if you turn the aquarium light off during the day, and the tank is in a relatively dark room, chances are pretty big that your betta fish will just go to sleep.

Is It Ok to Leave My Betta Fish in the Dark?

During the night it is OK to leave them in the dark, and in fact this is recommended. When it comes to daytime, no, betta fish should not be left in the dark. Betta fish need a good amount of light to see (seeing as they have relatively poor vision).

They are predators that need light to hunt, and on the flipside, they need light to ensure that they don’t turn into food for some other fish. So, during the day, no, it is not OK to leave them, in the dark.

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When all has been said and done, not betta fish cannot see in the dark and they really cannot see that well at all. Therefore, be sure to provide them with good light during the day, but be sure to turn it off during the night so they can sleep.

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