Tortoises have the best eyesight of all reptilian species, which enables them to navigate the world better, find nutritious foods, and avoid deadly predators and dangerous situations.
Tortoises can see 17 feet away, have excellent night vision, and see various colors. They can see bright colors, such as red, better than darker colors, such as blue.
Due to the position of their eyes, tortoises’ peripheral vision is excellent while still being able to see what’s in front of them.
Tortoises may not be the most active species, but it has nothing to do with their eyesight. Their color detection and night vision allow them to thrive in the wild.
How Far Can Tortoises See?
According to the Journal of Applied Animal Welfare Science, tortoises can see 17 feet away, although it’s possible that they can see even farther.
It is theorized that tortoise species that live in open areas, like Sulcata tortoises, can see farther than those living where there’s a lot of foliage, like yellow-footed tortoises.
Tortoises aren’t predatory animals, so they need to be able to see danger from afar to give them time to react. They’re slow-moving, solitary animals and can’t rely on a creep (a group of tortoises) for protection.
Also, seeing so far in the distance is beneficial when looking for food in vast expanses of land.
What Is a Tortoise’s Eyesight Like?
Tortoises have amazing eyesight, and they can see better than humans in many ways.
They have an advantage over other animals because of their eye placement. Looking at a tortoise, you’ll notice its eyes are further apart, almost to the side of the tortoise’s head.
Animals with eyes to the sides of their heads are classified as foraging animals; they need a wide view of the world to increase their chances of finding food. Look at any picture taken with a wide-angle lens, and you’ll get a good idea of how tortoises see the world around them.
However, if you compare tortoise eyes to other foragers, like parrots, you’ll notice that tortoise eyes aren’t as far apart. Having eyes that are slightly centered gives tortoises the ability to focus on objects and accurately measure distances.
They may not have full monocular vision and a wide horizontal field, but they have good depth perception, which is superior to most other forager animals.
Can Tortoises See in the Dark?
Tortoises can see in the dark and have surprisingly good night vision, even though they’re diurnal. Usually, animals active during the day and sleep at night have poor night vision.
There are various theories about why tortoises can see so well in the dark, including:
Tortoises move slowly. When out foraging, they may venture far away from their burrows. Whether or not they find food, they’ll sometimes have to find their way home in the dark.
Hiding from Predators
Tortoises are prey animals. Although they can deliver a painful bite, this isn’t effective against dangerous animals like snakes and coyotes.
When these predators hunt at night, tortoises need to be able to hide and avoid detection. Night vision is beneficial in these situations, and tortoises can quickly find a place to conceal themselves.
Lack of Sunlight
Some species live in areas where there’s lots of foliage. Because there’s minimal sunlight coming through, tortoises evolved to have good night vision.
Can Tortoises See Color?
Tortoises can see various colors. According to the University of Vienna, tortoises can distinguish between colors when visual cues are presented.
It’s a skill they need to find the right food to eat. As stated, tortoises are foragers who spend most of their time looking for sustenance in the wild.
Seeing color allows tortoises to identify foods they enjoy, avoid toxic plants or rotten fruits, and find food based on their nutritional needs.
Without this ability, they’d have to rely solely on their sense of smell. Sniffing every plant or fruit to check if it’s good to eat isn’t ideal, especially for slow-moving tortoises. They can speed up the process considerably thanks to their amazing color vision.
What Colors Can Tortoises See?
Tortoises can see a wide range of colors, including ultraviolet, which is invisible to the human eye. Tortoises even have favorite colors, preferring brighter colors, like red and yellow, over darker colors, like blue and green.
Tortoises interact more with brightly-colored materials. Researchers suggest that tortoises prefer such colors because of the colors of the fruits and plants they forage in the wild. Many of them have some red or yellow shade, so tortoises instinctively flock to those colors.
Can Tortoises See Red Light?
Of the bright colors a tortoise can see, red is a favorite.
When presented with something yellow, tortoises were more likely to approach if it was food. When presented with something red, tortoises interacted with it extensively, regardless of whether it was food. If your tortoise ever loses its appetite, offer red fruits to encourage it to eat.
Surrounding your tortoise with red light, which is unnatural in the wild, may confuse and disrupt its sleeping cycle or appetite.
Tortoise Vision vs. Human Vision
Tortoise vision is better than human vision in certain ways. For example, they have better night vision than humans because they have more rods in their eyes.
Photoreceptors, which are the cells located in the retinas, contain rods and cones. Cones are in charge of color reception, but rods are sensitive to light.
The more rods a creature has in its eyes, the better it can sense light, even in the dark. Tortoises can see ultraviolet light because they have more color receptors than humans.
Because their eyes are far apart, tortoises have superior peripheral vision than humans. Although humans can forage like tortoises, we are much better suited to work with binocular eyes like predatory animals. This gives us a better depth of field, so when it comes to measuring distances, we surpass tortoises.