How much does this conch with my eyes stare at me?

If one conch stare at you, how would you feel?

Picture source: pinterest

Picture source: cheezburger

Conch is secretly observing the source: gizmodo

Do you feel that the little snail in the sponge baby is looking at you with big eyes?

Picture source: Entrepreneur

Many people may not know that the conch has eyes. In fact, the conch not only has eyes, but also as big as it is in the picture. Shellfish with relatives with his relatives is much smaller than conch.

Don't think that its eyes are just decorations. In fact, its eyes are similar to head and foot -footed animals such as octopus, because the structure of the eyeball is similar to the camera, and it is also called camera Type Eye.

The picture below is the eyeball of Strombus Raninus, about 1.9 mm × 1.6 mm.

Picture source literature 1

This eye is like a small snail. There is a long, shrinkable eye handle connecting this eyeball, and the eyeball is composed of corneal, lens, vitreous, pigment cells, and rod beam.

The location of the conm organs, which is marked with the location of the eyes: Twitter

However, the eyes of conch and humans and other vertebrates are still different. It can even be said that the eyes of these low -level creatures are more "advanced" in structure.

Conch's Eye Source: Wikipedia

As shown in the figure below, in the eyes of the vertebrate (left), nerve fibers (2) in front of the retina (1), which means that light must be passed through the nerve fiber to reach the retina, blocking part of the light, causing the retina on the retina There is a area that cannot be sensible, and a blind spot is formed (4). In the eyes of conch and head and foot, nerve fibers will not block light or destroy the retina after the retina.

Picture source: wikipedia

In other words, human eyes have not been designed reasonably without conch. After all, people's eyes have no blind spots.

Human eyeball constructor source: Thoughtco

The crystal of the conch eyeball is closer to a spherical shape, and the crystal of the human eyeball is closer to an ellipse, which is flatter than the conch.

This difference is because the conch lives in water, and people are on the land. The medium that people look through the object are air, while the conch is through the water. The refractive index of the medium has led to the evolution of a aquatic conch with a higher refractive index spherical crystal.

Scientists have also found that the refractive index of the bell -shaped crystal shape of the conch is not uniform, and the refractive index is to decrease from the center to the outside and down to form a gradient.

Picture source: Reddit

The question comes, what is the use of such a slow -moving creature?

First of all, we have to know what it can see? And what it can see, a large part depends on the sensitivity of the eyeball to light.

Scientist Kirschfeld calculates a formula that calculates the absolute sensitivity of the eyeball to the light source through the pupil diameter, eye focal length, sensor beam length, sensor beam diameter, and light sensor's absorption coefficient.

A is the diameter of the pupil, F is the focal length of the eyeball, D is the diameter of the beam, x is the length of the beam of the rod, and k is the source of the light sensor absorption coefficient. Source: Literature 1

The average sensitivity of the absolute sensitivity of the eagle -wing conch at the Eagle Wing Conch was then calculated, while the human eye was only 0.023 μm2 (the unit means the number of photons that can be received per square meter). The absolute sensitivity to the light source of the eagle -wing conch is about 430 times that of human beings. In other words, conch's sensitivity to light is much higher than people.

High sensitivity to light can only be said that this creature will see more clearly in a weak light environment. Conch likes to act in dusk and evening, their eyes must definitely have higher sensitivity to light. But the light is slightly stronger, the eyes of the conch may not be able to stand it.

The value of the eyeballs between different creatures is compared to the RESOLUTION column to the retina resolution. The human eye resolution is about 60 times the conch.

But in terms of retina's resolution, conch is not as good as people (as shown in the above). Therefore, simply speaking, Conch has a pair of eyes sensitive but low -resolution, and can be seen clearly. It is more suitable than using the word of the eyes to call it the visual organs. If there is a fish swim in front of it, it is estimated that its eyes can only see a black shadow.

Picture source: twitter

But this vision is enough to use it. As long as it feels the changes in the light and shadow outside, it will immediately shrink the head back to the shell of shelter. People do not need to escape at all, they just need to shrink when they are aware of the danger.

The eye function of the scallops is similar to the eye function of the conch. However, although the eyes of scallops are small, the number is much more. There are about 200 eyes of a scallop, so compared to Brother Hajian, its light sensing range is wider. In addition, after it is aware of the danger, it will immediately applaud like it. In the aspect of escape ability, it can only be said that the scallops are slightly better.

Picture source: Clamsplaning

In addition, conch's eyes also have a special feature you can't think of, it will regenerate. In 2018, some scientists did an experiment on Conch and cut off their two eyes, but after 8 weeks, it had a pair of new eyes on the eye handle.

The regeneration process of conch eyes Source: Literature 2, from this point of view, human eyes will never be better than the eyes of the Shanghai snail.

Produced: Popular Science China

Author: Su Chengyu

Producer: China Science Popularization Expo

Edit: Wang Tingting

references:

Seyer J O. Structure and Optics of the Eye of the Hawk‐wing Conch, Strombus Raninus (L.) J. Journal of Experimental Zoology, 1994, 268 (3): 200-207.

Clark J M. RESTREION of Visual Performance and OPSIN Expression with the Retina During Eye Regency THE FLORIDA FIGHTING Conch (Strombus Alatus) J. 2018. 2018.

The China Science Popularization Expo is the Science Popular Science Platform of the Chinese Academy of Sciences. It is sponsored by the Computer Network Information Center of the Chinese Academy of Sciences. Relying on the high -end scientific resources of the Chinese Academy of Sciences, it is committed to spreading cutting -edge scientific knowledge and providing fun science and education services.

- END -