Turtles can see in the dark. They do not have night vision to see clearly in the dark. However, once their eyes adjust to the darkness, they can see things around them. In the dark, they see things more in red shade as they have Tapetum lucidum in their eyes, which is known as the redness gene.
Let’s now understand how turtles can see in the dark and if they have superior eyesight than humans.
How Do Turtles See In The Dark?
A turtle’s vision is similar to that of human vision with a slight difference.
In the dark, things look more on the reddish side to a turtle than humans.
Let’s understand how a turtle’s vision works with an example.
In complete darkness, we humans are not able to see things around us instantly.
It’s only after some time when our eyes get adjusted to the darkness that we are able to see things around us.
However, things are not as clear to us as in broad daylight.
A turtle’s vision is similar to humans in this context. In the dark, a turtle is not able to see immediately.
However, after a while, once the turtle’s iris adjust and allow more light into the eyes, the turtle is able to see in the dark.
It will not be able to see clearly though.
That is also the reason why you may sometimes find your pet turtle roaming around the tank.
Okay! Now that you know turtles can see in the dark, let’s find out if turtles have night vision like nocturnal birds or animals.
How Can We Verify That Turtles Don’t Have Night Vision?
If you have a pet turtle, you may have sometimes seen it roaming outside at night.
This may have made you wonder if a turtle has night vision. Turtles do not have night vision like owls.
Turtles’ eyes are not much different than humans.
Before we talk further about night vision, you need to understand what night vision is.
Night vision refers to the eyes’ capacity to see things clearly in low light.
Most of the nocturnal animals have night vision as they have tapetum lucidum in their eyes.
Tapetum lucidum refers to the layer of tissue in the eyes lying immediately behind the retina. It acts as a retroreflector.
It enhances the visual sensitivity in low light conditions.
It refers to the membrane in the eyes that sends back the photons in the eyes, thus enabling nocturnal animals to see clearly in the dark.
Now, to determine whether turtles have night vision, you need to simply take a photo of their eyes in the dark using your phone’s flash.
The animals that have night vision will have a glow in their eyes, and it will reflect in the photo.
On the contrary, the turtles’ eyes will not glow. This is a clear indication that turtles do not have night vision.
Alright! Since turtles do not have night vision and can see pretty much the same way as we do, is it necessary to keep the aquarium lights on at night?
Should Aquarium Lights Be On At Night?
Aquarium lights should not be on at night.
Turtles require adequate sleep at night for their well-being.
If you keep the aquarium light on at night, it will deprive your turtle of sleep. This will have an adverse effect on your turtle’s health.
You can keep the lights on at night if your turtle is awake or if you want to keep an eye on your pet.
Otherwise, there is no need to keep the aquarium lights on.
Besides, even if your turtle roams at night in the darkness, it will eventually be able to see once its eyes adjust to the darkness.
Can Turtles See Underwater?
It is difficult for humans to see long-distance underwater. However, the same is not true for turtles.
Turtles can see underwater as clearly as they can see on land.
So, what sets turtles apart? How can they see things better underwater than humans?
There is not much of a difference between turtles’ vision and human vision.
Still, turtles can see better underwater as they live in water, and their eyes have adapted to see underwater.
In water, turtles’ eyes produce mucus.
This mucus forms a protective layer on their eyes and keeps their eyesight unharmed by the water’s salt and bacteria.
The mucus looks more like tears, and you may mistake it for turtles’ crying. Mucus is not tears.
The mucus helps in excreting excess salt from turtles’ bodies through their eyes.
The only hindrance to clear vision underwater is dirt. If the water is polluted, turtles cannot see clearly.
However, this is rarely the case in the wild as the water is usually clean.
But in captivity, if the tank water is contaminated, it will affect the eyesight of your turtle.
Your turtle will then not be able to see clearly.
Points To Remember
Turtles can see in the dark after adjusting their eyes to the darkness around them.
They have more receptors in their eyes compared to humans. However, they do not have night vision.
Turtles can even see underwater without much difficulty.
The only hindrance to their eyesight in water is the dirt or bacteria. Turtles struggle to see in polluted water.
Turtles do not require the aquarium lights at night.
Keeping the lights on at night will deprive your turtle of peaceful sleep and will hamper its health.
Turtles see things more in red color shades than humans as they have the redness gene.
