If we examine the eye of an insect under a strong magnifying glass, we will see that it consists of a tiny round lattice. And this seems to be due to the fact that the insect’s eye consists of many small eyes, scientifically called “facets”. Today we are trying to understand why insects have round eyes, how do insects see the objects around them? These often interest the child, but?
Insect eyes are divided into three types:
The structure of these eyes is different, and insects are not equally capable of seeing with them.
The complex structure of the eyes predominates in maximum quantity insects depends on the development of the living creature itself. Such eyes consist of multiple individual structural elements - ommatidia.
Light is transmitted and refracted through them, and visual signals are perceived. Each individual ommatidia is distinguished by the presence of a pigment isolation apparatus, which completely or partially protects from the entry of side light.
Ommatidia are divided into two main types, which affects the structural features of the eyes.
Simple eyes include the organs of vision that are found in some insects and are usually located on the top of the head.
The structure of such eyes is significantly simplified; they see weaker than others. It is believed that such eyes are completely devoid of visual ability, and are only responsible for improving the functions of compound eyes.
And if you paint over the facets of an insect, it will not be able to navigate in space, even if it has well-defined eyes of a simple structure.
Larval eyes are the organs of vision that insect larvae have, which have the ability to completely transform into compound eyes. Their structure is somewhat simplified, which does not allow the insect to see well.
Insect vision has been studied for a long time. Thanks to the increased interest of scientific specialists, it was possible to find out a lot distinctive features related to eye performance.
And yet, the structure of the visual organs is so different that the quality of image perception, color, volume, movement different groups insects are different. Some factors influence this:
Insect eyes with different numbers of ommatidia:
Insects see differently: the visible spectrum of light is reduced on the left side and increased on the right.
In a dragonfly, only the lower facets distinguish colors, the upper ones distinguish shape. The dragonfly's eyes occupy most of the head, so the dragonfly is able to see and feel what is happening behind its back. The dragonfly does not see the object, but feels its heat and sees it in the infrared range.
Insects are able to distinguish shapes, but this does not happen in the same way as in humans. Butterflies and bees will ignore a circle or oval, but will be attracted by a radial structure that resembles a flower corolla. An object characterized by the complexity of its figure and play of shadows will attract attention much more quickly. It is also interesting that bees like objects that are small in size.
It is noteworthy that insects are able to “recognize” objects even by location.
Each of us who has at least once tried to get rid of an annoying fly by running after it with a firecracker in hand knows very well that this task is not always easy to accomplish, and sometimes it is completely impossible. The reaction of the gray-black small tenant is just right. The point is that you are not her competition. Why? Read the article in which we will tell you all about winged pests.
In what way is this fly superior to us:
We, representatives of the human race, who consider ourselves so perfect and omnipotent, have only binocular vision allowing you to focus on specific object or in a certain narrow area in front of us, and are in no way able to see what is happening behind us, but for a fly this is not a problem, since its vision is panoramic, it sees the entire space at 360 degrees (each eye is capable of providing a view of 180 degrees).
In addition, these insects are not just thanks to anatomical structure their visual apparatus can see in different directions at once, but they are also able to purposefully survey the space around them. AND all this is provided located on the sides with two large convex eyes that stand out clearly on the insect’s head. Such a huge field of vision determines the special “insight” of these insects. In addition, they need significantly less time to identify objects than we humans do. Their visual acuity is also 3 times greater than our human one.
If you examine the eye of a fly under a microscope, you can see that it is made up, like a mosaic, of many small sections - facets - hexagonal structural units, externally shaped very similar to a honeycomb. Such an eye accordingly called facet, and the facets themselves are also called ommatidia. There are about four thousand such facets in the eye of a fly. They all give their image (a small part of the whole), and the fly’s brain forms the overall picture from them, like from a puzzle.
Panoramic, facet vision and binocular vision, which is characteristic of people, have diametrically opposite purposes. For insects to be able to quickly navigate and more notice approaching danger, but also to have time to avoid it, it is important not to see a specific object well and clearly, but, mainly, to carry out timely perception of movements and changes in space.
There is another curious feature of the fly’s visual perception of the surrounding world, regarding the color palette. Some of them, so familiar to our eyes, cannot be distinguished by insects at all, others look different to them than to us, in different colors. As for the colorfulness of the surrounding space - flies differentiate not only the seven primary colors, but also their subtlest shades, because their eyes are able to see not only visible light, but also ultraviolet, which people, alas, are not allowed to see. It turns out that in the visual perception of flies the world around us more rosy than people's.
It should also be noted that, having certain advantages visual system, these representatives of the six-legged world (yes, they have 3 pairs of legs) cannot see in the dark. At night they sleep, as their eyes do not allow them to navigate in the dark.
And these small and nimble creatures notice only small and moving objects. An insect does not perceive such a large object, for example, like a person. But approaching human hand The fly's eyes see perfectly and immediately transmit the necessary signal to the brain. Also, it will not be difficult for them to see any other rapidly approaching danger, thanks to the complex and reliable structure of the eyes, which allows the insect to see space in all directions at the same time - right, left, up, back and forward and react accordingly, saving itself, which is why they are so difficult slam.
Numerous facets allow the fly to follow very fast moving objects with high image clarity. For comparison, if a person's vision can perceive 16 frames per second, then a fly has 250–300 frames per second. This property is necessary for flies, as already described, to detect movements from the side, as well as for their own orientation in space during fast flight.
By the way, in addition to two large compound compound eyes, the fly has three more simple ones located on the frontal part heads in the interval between the facets. In contrast to the complex ones, these three are needed in order to see objects at close range, since the complex eye in this case is useless.
Thus, to the question of how many eyes a housefly has, we can now accurately answer that there are five:
Compound eyes located in flies on the sides of the head, and in females the location of the organs of vision is somewhat expanded (separated by a wide forehead), while in males the eyes are a little closer to each other.
Both flies and bees have five eyes. Three simple eyes are located at the top of the head (one might say, on the crown), and two complex, or facet, eyes are located on the sides of the head. The compound eyes of flies, bees (as well as butterflies, dragonflies and some other insects) are the subject of enthusiastic study by scientists. The fact is that these organs of vision are arranged in a very interesting way. They are made up of thousands of individual hexagons, or, in scientific terms, facets. Each of the facets is a miniature peephole that gives an image of a separate part of the object. The complex eyes of a housefly have approximately 4,000 facets, a worker bee has 5,000, a drone has 8,000, a butterfly has up to 17,000, and a dragonfly has up to 30,000. It turns out that the eyes of insects send several thousand images to their brains individual parts an object, which, although they merge into the image of the object as a whole, still this object looks like it is made of a mosaic.
Why are compound eyes needed? It is believed that with their help insects orient themselves in flight. While simple eyes are designed to look at objects that are nearby. So, if a bee's compound eyes are removed or covered, it behaves as if it were blind. If the simple eyes are sealed, then it seems that the insect has a slow reaction.
1,2
-Compound (compound) eyes of a bee or fly
3
-three simple eyes of a bee or fly
Five eyes allow insects to cover 360 degrees, that is, to see everything that happens in front, on both sides and behind. Maybe that’s why it’s so difficult to get close to a fly unnoticed. And if you consider that compound eyes see a moving object much better than a stationary one, then one can only wonder how a person sometimes manages to swat a fly with a newspaper!
The ability of insects with compound eyes to capture even the slightest movement is reflected in the following example: if bees and flies sit down with people to watch a movie, it will seem to them that bipedal viewers are looking at one frame for a long time before moving on to look at the next. In order for insects to watch a movie (and not individual frames, like a photo), the projector film needs to be spun 10 times faster.
Should we envy the eyes of insects? Probably not. For example, the eyes of a fly see a lot, but are not capable of looking closely. That's why they discover food (a drop of jam, for example) by crawling across the table and literally bumping into it. And bees, due to the peculiarities of their vision, do not distinguish the color red - for them it is black, gray or blue.
The ability to see the surrounding reality in all its diversity of colors and shades is a unique opportunity that nature has given to man. Insects, like humans, also have an organ of vision, but they perceive the world of colors differently. Modern scientists, using special instruments, have managed to get a little closer to solving the mystery and understand how insects see objects, colors and different shapes.
Different insects have different organs of vision. If some representatives of the invertebrate class can only distinguish light from darkness or observe the world in black and white, then others are able to recognize colors or even see everything in the ultraviolet spectrum.
The ability to see in insects is somewhat different from the vision of other living creatures. Some species have several pairs of eyes, which can be located not only on the head, but also on other parts of the body. Insects don't discriminate small parts and see only at a distance of 1-2 meters. They can navigate well at sunset thanks to their ability to determine the plane of polarization of light. They distinguish the blinking of light waves tens of times better than people. Insects perceive the world around them in three ways:
The clarity of the image varies among different representatives of the invertebrate class and depends on the role that visual perception plays in their life. Some can only see the outlines of objects, others imagine objects as elongated, and still others see clear and proportional images.
It has long been known that some species of insects distinguish colors well, and the range of shades they perceive differs from that of humans. Color vision plays a significant role in the life of these arthropods. They recognize signals flowering plant(smell, color of corollas) and find flowers with the necessary nectar or pollen. Insects, having found suitable flower, remember its details, which later helps them find the right plant and save time during the pollen collection period.
How do insects see?
A fly sharply dodges an object flying at it, a butterfly chooses a certain flower, and a caterpillar crawls to the tallest tree. Insects, like people, also have visual organs, but they see and perceive the world in a special way. With his exceptional vision, inaccessible to humans. Some insects can only determine light and dark, while others are well versed in shades. So how do insects see the world?
Their ability to see is divided into three ways.
An interesting feature in which it is not necessary to have eyes. But its big disadvantage is that the insect can only distinguish light from darkness. It does not see any objects or colors. How does it work? The light passes through the cuticle, the outer layer of skin, and reaches the insect's head. There a reaction occurs in the brain cells, and the insect understands that light is falling on it. Such a device is not available to everyone, but it is very helpful for those insects that live underground, for example, earthworms or blind cave beetles. This type of vision is found in cockroaches, aphids and caterpillars.
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What is pollen for?
Insects with simple eyes are luckier. They can not only determine darkness from light, but also distinguish between individual objects and even their shape. Such eyes are most often found in insect larvae. For example, mosquito larvae have pigment spots instead of eyes that capture light. But caterpillars have five to six eyes on each side of their heads. Thanks to this, she is well versed in forms. But she sees vertical objects much better than horizontal ones. For example, if she has to choose a tree, she will rather crawl to the one that is taller than to the one that is wider.
Such eyes are most often found in adult insects. You can identify them immediately - they are usually located on the sides of the head. Compounded eyes are much more complex and varied than all the others. They can recognize the shapes of objects and identify colors. Some insects see well during the day, while others see well at night. An interesting feature of these eyes is that they do not see the whole picture, but only pieces. And already in the brain, the insect puts together a puzzle from the received images in order to see the full picture. How does a fly manage to connect all the pieces of a fragment in flight? Surprisingly, it is in flight that she sees better than at rest. And for a landing site, any insect is more likely to choose something that moves or sways.
