Why are frog eyes so big?

Why Do Woodpeckers Have That Long Beaks?

The frog's head has a limited range of activity and wants to live, so what are the structural characteristics of the frog's eyes with big eyes, so that the frog has such a strange ability? After in-depth research, scientists have found that the retina of frog eyes is composed of three layers of cells: the photoreceptor cell layer, the intermediate contact cell layer, and the ganglion cell layer.

The photoreceptor cells in the first layer convert images of external objects into images on the retina and convert the images into electrical nerve signals. The second layer of contact cells is responsible for transmitting electrical signals to the third layer; The third layer of ganglion cells detects image features and codes these electrical signals to the brain.

Ganglion cells are further divided into four categories, each of which performs a specific detection function and only responds to a certain feature of the moving target, identifying and extracting different features of the retinal image. In this way, a complex image is broken down into several easily recognizable features, improving the speed and accuracy of target discovery and identification. Therefore, scientists call these four types of ganglion cells "detectors", which are "edge detectors", "convex edge detectors" (also called "insect detectors"), contrast detectors, and "dimming detectors".

Together, these four detectors allow the frog to respond only to the objects that are critical to its survival.

The edge detector only reacts to the edges of the surrounding light or dark scenes; The convex edge detector only reacts to the curved convex edge of the scene that moves like an insect; contrast detector, which only reacts to changes in brightness; The dimming detector, on the other hand, only reacts to the decrease in light intensity, i.e., shadows. Taken together, the frog's eyes are particularly sensitive to both "fast-moving objects with rounded fronts" – insects that it likes to eat, and predators that are "fast-moving with large shadows". It does not respond to things that have no meaning to its existence, such as trees and blades of grass that do not move or shake.

It is not difficult to see that the frog's eye plays a role far beyond the scope of the camera that captures the scene without leaking a bit. The frog's eye can not only present images of the objects seen on the retina, but also analyze the images it sees, pick out specific image features, and then "communicate" to the brain through the optic nerve.

After the "meticulous carving" of nature, this visual inspection system of frog eye has reached a very perfect point. The frog's eye does not react to the background, instead focusing on objects that move relative to the background and have specific morphological characteristics. As soon as the "shadow" of an insect or predator passes in front of its eyes, it immediately reacts by pounceing on food or escaping into the water.

In other words, the frog's eye sees only what is meaningful to its survival. For example, the natural predators of movement and food are very important to its survival, and the pond is its habitat and is a meaningful sight for its survival. This characteristic of the frog's visual organ provides a design principle and model for the "moving target detector".

In order to aim at the flying insects, swallow them in one bite.

Sentence formation: 1. The frog's eyes are big and round, like two soybeans that have been put up.

2. The frog's eyes are big and round, and they look like two big lights of a car when they open and close.

Hope it helps.

The previous sentence of "little frog with big eyes" is that the river is clear and the weather is fine. From the second volume of the first grade of primary school Chinese "Little Frog" of the newcomer education version: the river is clear and the weather is clear, and the little frog has big eyes.

Protecting seedlings from eating pests has done a lot of good things. Please take care of the little frogs so that the seedlings do not get sick.

Frogs (frogs) belong to the phylum Chordates, amphibians, anceridae, and amphibians of the frog family, adults without tails, eggs laid in water, fertilized in vitro, hatched into tadpoles, respiration with gills, after mutation, adults mainly use lung breathing, and also use ** breathing. The upper jaw has teeth, usually vomer teeth. shoulder girdle fixed thoracic type, vertebral body uneven type, recommended vertebral transverse process columnar; There is no intermediated cartilage between the two bone nodes at the end of the toes.

The tympanic membrane is distinctly hidden under the skin,** smooth or with wart grains. The tongue is generally oblong, and the posterior end is mostly notched.

The frog's eyes are indeed very special, it can't see the static things in front of it clearly because the frog's eyes do not move the eyelids, because when the object is stationary, the frog cannot perceive its existence, and only the moving object can attract the frog's attention. In addition, although the frog's eyes are large, they are actually short-sighted, so only things that move in front of the frog can attract the frog's attention, and even if it is moving too far, it cannot see clearly.

The process of frog predation Although the frog needs to move the object when predating, the frog also has a strong ability to distinguish, if there are a variety of small insects flying in front of the frog, the frog's eyes can quickly distinguish their favorite food creatures, it can use different images, these small animals in motion can be quickly excited to locate and analyze, once the analysis is completed, the frog's eyes will only stare at their target, and other small animals in motion are not attractive to the frog.

The frog can then quickly determine the position of the creature, and then use the frog's tongue to attack the food quickly and accurately. Therefore, when the fly appears at the same time as other animals, it will be found that the frog will always be able to catch the fly at the first time, because it may only see its favorite fly.

The eyes of the frog The frog's eyes are not able to shake and tremble, its eyeballs are more prominent, such an eye structure also makes the frog born short-sighted, so it has no way to react to the stationary objects around it, only when the animal is moving, can it form a picture in its eyes, otherwise the still object in its eyes is not painted withered eggplant noodles, just like it does not exist.

Therefore, even if there are a lot of parked flies around the frog, as long as it does not fly, the frog does not know that it is surrounded by food, as long as they fly, the frog can locate immediately. So if you don't move around the frog, you can't actually notice it.