There pupil form In terrestrial animals it is not accidental, but it is closely related to theirs ecological nichein particular to their role of predator (crocodile) or prey (goats) and their habits and activities. Two of the most distinctive forms are the pupils horizontal or rectangular And verticaleach with specific optical advantages that favor survival as explained by the article published on Science by US and British researchers entitled Why Do Animal Eyes Have Pupils of Different Shapes?. In fact, as reported by the study, the pupils in crack are considered evolutionary adaptations And their form is the result of natural selection. The presence of different pupils in species not strictly related suggests that these forms have evolved several times independently, in response to similar selective pressures. The Circular pupilsInstead, they are a common form, present in a variety of animals, including us humans and many daytime predators or some species active at different times of the day.
Eyes with horizontal pupils: goats, horses and sheep
The horizontal pupils and rectangular shape are commonly observed in the species that are prey Like sheep, goats, horses. These species tend to have eyes positioned laterally on the head. This feature offers optical and functional advantages for their habits and for the environment in which they live. First of all, the eyes with horizontal pupils guarantee one remarkable panoramic vision optimizing and maximizing the horizontal one and a Large monocular visual field (the area seen by a single eye). This is a crucial aspect for the prey, which must be able to detect predators who approach various directions.
The horizontal pupils also offer a Chiara frontal vision and reduce the minimum blur of the horizontal contours, which is particularly advantageous to move quickly on irregular landsince it allows them to clearly see the ground in front and behind them. Another “trick” that these animals can boast thanks to their eyes is the ability to maintain thealignment of the pupil with the ground Even when the head is inclined, taking advantage of the advantages mentioned above during movement and pasture.
Vertical pupils are useful for night predators such as crocodiles
The vertical pupilson the other hand, they are more common in predators from ambush such as cats, foxes and crocodiles. These predators tend to be active both during the day and at night by drawing several benefits:
- Distance estimate: The vertical pupils create an astigmatic field depth that helps predators from ambush to precisely estimate the distance from the prey. This particular form of pupil optimizes the vision of vertical contours, crucial for the identification and accurate location of the prey, especially in complex environments where the perception of the depth is fundamental for an effective attack.
- View in Variable Light Conditions: Being cracking they offer a wide range of retinal lighting control. This is advantageous for ambush predators who can be active both in intense and low light conditions. The vertical pupils are like cracks that can become very narrow or very wide. This allows the animal to check how much light enters their eyes.
- Complementary use of disparity and blur: Predators with front eyes, such as cats, use binocular vision (3D) together with the blur, taking advantage of their vertical pupils, to precisely estimate the distance from the prey.
An effective general vision with circular pupils
The Circular pupils They are a common form, present in a variety of animals, including humans, many day predators and some species active at different times of the day. Allow a vGeneral ision effective, suitable for a variety of visual tasks. They are particularly common in animals active during the daywhere the light is abundant and the need for extreme light of light could be less critical than night animals. Many predators who actively hunt during the day have circular pupils who support the necessary vision to chase and capture the prey in bright environments. Although the circular pupils can dilate and contract to regulate the amount of light that enters the eye, their adjustment range could be lower than the slot pupils (horizontal or vertical).
