What animals can't see green? Unveiling the secrets of animal vision.
In nature, animals' visual systems exhibit significant differences due to their habitats, habits, and biological evolution. Some animals possess highly developed color vision systems, capable of distinguishing multiple colors; while others have relatively limited vision, or even cannot see certain colors at all. Green , for example, may be an indistinguishable color for many animals.
This article will reveal which animals cannot see green and explore their visual characteristics and their impact on survival.
1. How do animals perceive color?
In most animals, color vision depends on cone cells, photoreceptors in the retina. Cone cells respond to different wavelengths of light, thus helping animals distinguish colors. Humans typically have three types of cone cells, sensitive to red, blue, and green respectively, hence the term trichromatic vision. In contrast, many animals have simpler color vision systems, and some cannot even see green.
2. What are some animals whose green color cannot be seen?
(1) Dog
Dogs have a different visual system than humans; they are dichromatic, meaning they only have two types of cone cells. This means dogs can see blue and yellow, but not red and green. In a dog's eyes, green is usually perceived as gray or yellow. Therefore, many green toys or environments do not present a clear color difference to a dog.
(2) Ox
Like dogs, cows are dichromatic, meaning their cone cells are sensitive to blue and yellow. This makes it impossible for cows to distinguish green, and even red is as difficult to distinguish as green in their eyes. Therefore, the traditional saying that "a red cloth angers a cow" is unfounded; the cow's aggressive reaction is actually due to the movement of the cloth, not the color red.
(3) Cetaceans and dolphins
Most marine mammals, such as whales and dolphins, live in underwater environments and their color vision differs significantly from that of land animals. They are typically monochromatic , meaning their cone cells are of only one type and cannot distinguish any colors, including green. This visual characteristic makes them rely more on changes in brightness than on color in the dark underwater environment.
(4) Shark
Sharks also lack color perception, especially the ability to recognize green. Their eyes are adapted for hunting in the deep sea, capable of sensing brightness and movement, but their color discrimination is extremely poor. This makes sharks rely more on other senses, such as smell and electroreceptors, rather than color perception, when identifying prey.
(5) Rats
Mice are also dichromatic visioners; they can see blue and yellow, but cannot distinguish red and green. A mouse's visual function is primarily adapted for nocturnal activity, so its photoreceptor cells are better suited for detecting brightness and movement than color.
3. Why can't these animals see green?
The evolution of animal vision is closely related to its habitat and lifestyle. For nocturnal or marine animals, color perception is often less important than brightness and movement. Therefore, many animals have abandoned some color perception abilities during evolution in order to focus their visual functions on changes in light intensity and tracking movement.
For example:
Marine animals : In the deep sea, light is greatly reduced, making color perception almost meaningless. Animals such as sharks and whales rely more on their visual sensitivity in low-light conditions than on their color perception.
Nocturnal animals : Animals like mice move in the dark and rely more on their sensitivity to light and shadow than on their color recognition.
4. The impact of green is not visible.
Although these animals cannot see green, this does not mean their visual abilities are weak. On the contrary, their visual perception in other areas (such as brightness and motion) is usually very acute, compensating for their poor color vision. For example:
Dogs : Although they cannot see green, they can perceive movement and changes in their environment through strong contrasts in brightness.
Whales : Although they cannot see green, they are very sensitive to changes in light and electric fields in the underwater environment, which helps them hunt in dark waters.
While humans possess a powerful ability to perceive color, enabling them to see a wide range of hues, including green, many animals have chosen different paths in visual evolution. Animals such as dogs, cows, whales, sharks, and mice, due to their unique living environments and needs, are unable to perceive green. This difference in visual characteristics not only demonstrates the diversity of nature but also reminds us of the unique ways animals perceive the world.
