Turtles are the reptiles of order Testudines that have been roaming on Earth before the Permian period. Presently, there are more than 360 living species of turtles. Many turtle lovers have raised a question on Turtle’s vision, “Can turtles see color,” or “are they colorblind.”
The answer to the question is: Turtles are not colorblind, and they can see red, green, blue, and ultraviolet colors with more shades than humans. Turtles are tetrachromatic and can perceive a more comprehensive range of electromagnetic spectrum compared to us. They can distinguish millions of color shades and see the world more in red, orange, and yellow hues.
Also, turtles have a gene-encoded enzyme, CYP2J19, that assists them in distinguishing various shades of red that are invisible to the human eye.
Turtles have unique eyesight that helps them to find prey in deep water. Later in this post, we have explained more on Turtles Vision and answered many relevant questions regarding this topic. So, without any further ado, let’s begin.
Can Turtles see color?
Turtles can see millions of color shades. According to the recent experiment, it is proven that they are not colorblind and have more cones than humans in their eyes.
Turtles are tetrachromats means the cones in their eyes can perceive red, green, and blue colors along with ultraviolet light. On the opposite side, humans are trichromats and can perceive only red, green, and blue color variations.
In addition, turtles also have advanced ultraviolet vision compared to fish, which helps them to recognize their prey better underwater. Since the dinosaurs’ period, their eyes have been developed to witness clearly both in water and on land.
Turtles’ advanced vision can sense UVA and UVB lights from wavelength 300 to 370 nm. Many fish have only UVA vision, but turtles gain underwater superiority by perceiving UVB lights.
In a nutshell, turtles can see colors from wavelength 300 to 370 nm and 400 to 740 nm. At the same time, humans can perceive only visible spectrum from approximately 400 to 720 nm.
Not only this, but turtles also have the red gene called CYP2J19, which is believed to be inherited from a 250 million-year-old creature called archosaur. Both birds and turtles share this red gene that grants them the ability to sense multiple shades of red.
However, unlike birds, turtles see the world more in red, orange, and yellow hues. It permits them to navigate and find the prey both in water and on land. Below is the image of how turtles see the world.
As the image illustrates, turtles sense their surroundings more in red, orange, and yellow shades with other hues in the daytime. And during the night, they rely on their ultraviolet vision to sense their environment.
Are Turtles colorblind?
Previously, researchers thought that turtles were colorblind and witnessed the world in gray shades. But after performing many experiments and research, it is noticed that they can perceive more colors than numerous animals.
Their eyes are evolved in such a way to recognize various colors both in water and on land. They have four types of cones in their eyes that are sensitive towards red, green, blue, and ultraviolet light.
In addition to the CYP2J19 gene, turtles can distinguish more variations of red color that are invisible to the human eye, which is why turtles see the environment more in red, orange, and yellow shades.
An experiment was performed where turtles of different species are receiving foods from a particular color straw. After some time, it was noticed that turtles show different behavior towards this particular color straw compared to other colored straws (where turtles show no specific response).
Can Turtles see in the Dark?
Turtles cannot see very well in the dark. Unlike nocturnal animals, they do not have tapetum lucidum, a thin light-reflective membrane in their eyes. Also, their eyes do not comprise too many rods like night animals.
Like humans, turtles are only able to distinguish objects in black shades at night. Their night vision is the same as humans but with extra colors and ultraviolet light. Below we have inserted the image of how turtles see in the dark.
As you can see, turtles can see precisely the same as humans with more red colors because of the CYP2J19 gene. In the dark, humans are not capable of seeing anything immediately.
It usually takes thirty minutes for the human eye to adjust at night completely. After changing, we can visually glimpse the shapes of the objects with black shades. The same thing happens with turtles also.
Their eyes have been evolving since the Permian period to navigate in the dark. They can notice things to some extent, like us. Also, the ability to sense ultraviolet glows assists them in finding their prey even in the dark.
Even inside the water, turtles’ vision remains the same and glimpse the exact things with identical colors. However, they can see very far in the water corresponded to land. That’s why many species of turtles like to feed on aquatic animals rather than hunt on the land.
Note- Turtles cannot see anything in complete darkness.
How do Turtles see the world?
Turtles see the world in red, orange, and yellow shades with detail. They have a clear vision and can also perceive ultraviolet light (UVA and UVB), where the visual sensitivity of many fish drops off.
According to the research, it is proven that turtles are far-sighted underwater and nearsighted on the land. Here, near-sighted means they cannot focus on far entities.
Most turtles are aquatic and spend most of their life span inside the water. They also hunt aquatic prey like fish. Therefore, they require excellent underwater vision to carry out daily underwater activities.
Turtles’ eyes have flat corneas and spherical lenses that assist them to see very far with detail underwater where the light comes after refraction. Their eyes are evolved to sense refractive light inside the water much better than the land. However, in the dirty water, they are not able to see very far.
Also, dirty water comprises many harmful bacteria that may affect their eyes. Hence to overcome this, they form tears. Turtle tears contain mucus that covers their eyes, allowing them to witness even in the dirty water and protecting their eyes from harmful bacteria and dirt.
How do Turtles see humans?
Turtles can clearly see humans and recognize us based on our physical appearances. They have a clear vision and differentiate us as another common land animal.
Also, due to the presence of the CYP2J19 gene, they see humans more in red, orange, and yellow shades. In the water, turtles can notice humans from a very distant. In conclusion, an excellent healthy adult turtle has the same vision as us with more red shades.
Turtle vision vs Human vision
|Turtle vision||Human vision|
|Turtle Vision is tetrachromatic.||Human Vision is tetrachromatic.|
|Have four types of cones that are sensitive to red, green, blue, and ultraviolet.||Have three types of cones that are sensitive to red, green, and blue.|
|Having CYP2J19 gene allows them to see various shades of red color.||Does not have CYP2J19 gene.|
|Can see underwater.||Cannot see underwater.|
Here, we conclude our article on, “Are Turtles colorblind or can Turtles see color,” along with other explanations. We hope you like this post. We will be back with another article. Till then, stay healthy; stay tuned.
Seeing red to being red: conserved genetic mechanism for red cone oil droplets and co-option for red coloration in birds and turtles by The Royal Society
Monty is a founder of How It See. Being a life science student in a reputed university, he always wonders about an eclectic correlation between science and nature. After engaging in various college projects, Monty determined to share all his knowledge with you as a writer. In the meantime, he loves to research and study about the various types of colorful animals.