How fast does a fly see? How many eyes does a fly or bee have? Features of the visual abilities of flies

Amazing unusual eyes the common fly has!
For the first time, people were able to look at the world through the eyes of an insect in 1918 thanks to the German scientist Exner. Exner proved the existence of unusual mosaic vision in insects. He photographed a window through a firefly's compound eye placed on a microscope slide. The photograph showed an image of a window frame, and behind it the blurry outline of a cathedral.

The fly's compound eyes are called compound eyes and are made up of many thousands of tiny, individual hexagonal facet eyes called ommatidia. Each ommatidium consists of a lens and an adjacent long transparent crystalline cone.

In insects, the compound eye can have from 5,000 to 25,000 facets. The eye of a housefly consists of 4000 facets. The fly's visual acuity is low, it sees 100 times worse than a man. Interestingly, in insects, visual acuity depends on the number of facets in the eye!
Each facet perceives only part of the image. The parts are put together into one picture, and the fly sees a “mosaic picture” of the surrounding world.

Thanks to this, the fly has an almost circular field of view of 360 degrees. She sees not only what is in front of her, but also what is happening around and behind her, i.e. large compound eyes allow the fly to look in different directions at the same time.

In the eyes of a fly, reflection and refraction of light occurs in such a way that the maximum part of it enters the eye at a right angle, regardless of the angle of incidence.

The compound eye is a raster optical system in which, unlike the human eye, there is no single retina.
Each ommatidia has its own diopter. By the way, the concept of accommodation, myopia or farsightedness does not exist for a fly.

A fly, like a person, sees all the colors of the visible spectrum. In addition, the fly is able to distinguish between ultraviolet and polarized light.

The concepts of accommodation, myopia or farsightedness are not familiar to the fly.
The eyes of a fly are very sensitive to changes in light brightness.

Studying the fly's compound eyes showed engineers that the fly is capable of very accurately determining the speed of objects moving at enormous speeds. Engineers have copied the principle of flies' eyes to create high-speed detectors that detect the speed of flying aircraft. This device is called the "fly's eye"

Panoramic camera "fly's eye"

Scientists at the École Polytechnique Fédérale de Lausanne have invented a 360-degree camera that allows images to be transformed into 3D without distorting them. They proposed a completely new design, inspired by the design of a fly's eye.
The shape of the camera resembles a small hemisphere the size of an orange; along the surface there are 104 mini-cameras, similar to those built into mobile phones.

This panoramic camera provides a 360-degree 3D image. However, each of the composite cameras can be used separately, transferring the viewer’s attention to certain areas of space.
With this invention, scientists solved two main problems of traditional movie cameras: unlimited angle of view and depth of field.

FLEXIBLE CAMERA 180 DEGREES

A team of researchers from the University of Illinois, led by Professor John Rogers, has created a faceted camera that works on the principle of an insect's eye.
A new device in appearance and in its own way internal structure resembles the eye of an insect.

The camera is made up of 180 tiny lenses, each with its own photo sensor. This allows each of the 180 micro-cameras to operate autonomously, unlike conventional cameras. If we draw an analogy with the animal world, then 1 microlens is 1 facet of a fly’s eye. Next, the low-resolution data obtained by micro-cameras enters a processor, where these 180 small pictures are assembled into a panorama, the width of which corresponds to a viewing angle of 180 degrees.

The camera does not require focusing, i.e. Objects that are close can be seen just as well as objects that are far away. The shape of the camera can be not only hemispherical. It can be given almost any shape. . All optical elements are made of elastic polymer, which is used in the manufacture of contact lenses.
A new invention may find wide application not only in security and surveillance systems, but also in new generation computers.

Both flies and bees have five eyes. Three simple eyes located in the upper part of the head (one might say, on the crown), and two complex, or facet ones, 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!

Feature of insects with compound eyes capture even the slightest movement displayed in following example: If bees and flies sit down with people to watch a movie, it will seem to them that two-legged viewers are looking at one frame for a long time before moving on to 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 brain of a fly is hardly larger than the hole in a sewing needle. But a fly, having such a brain, manages to process more than a hundred static images (frames) per second. As you know, the human limit is approximately 25 frames per second. And the fly found a simpler and effective method image processing. And this could not but interest researchers in the field of robotics.

Flies were found to process 100 frames per second. And this allows them to detect an obstacle during flight within a few milliseconds (a millisecond is one thousandth of a second). In particular, the researchers focused their attention on optical flows, which they called "optical field flows." It appears that this optical field is processed only by the first layer of neurons. They process the “rough” source signal from each fly “pixel”. And they send the processed information to the next layer of neurons. And, according to the researchers, there are only 60 of these secondary neurons in each hemisphere of the fly brain. However, the fly brain manages to reduce or fragment the field of view into many sequential “motion vectors” that give the fly a vector of direction of movement and “instantaneous” speed. And what’s interesting is that the fly sees it all!

We, people (and not everyone), know what a vector and instantaneous speed are. And the fly, naturally, has no idea about these things. And such abilities of the fly’s brain to process great amount one can only envy the information. Why do we see only about 50 frames per second, and the fly 100? It's hard to say, but there are reasonable guesses on this matter. How does a fly fly? Almost “instantly”, with enormous acceleration. We could hardly withstand such an overload. But it is possible to create a robotic brain that is as fast as the brain of a fly in processing information flows.

To try to understand how a tiny fly brain can process such a huge amount of information, researchers in Munich have created a “flight simulator” for a fly. The fly could fly, but was kept on a leash. Electrodes recorded the response of the fly's brain cells. And researchers tried to understand what happens in the fly’s brain during flight.

The first results are obvious. Flies process images from their fixed eyes very differently than humans do. When a fly moves in space, “optical flux fields” are formed in its brain, which give the fly the direction of movement.

How would a person see it? For example, when moving forward, surrounding objects would instantly scatter to the sides. And objects in the field of view would appear larger than they actually are. And it would seem that nearby and distant objects move differently.

The speed and direction with which objects flash before the eyes of a fly generate typical patterns of motion vectors - field flows. Which, at the second stage of image processing, reach the so-called “lobula plate” - the center of vision more high level. Each hemisphere of a fly's brain contains only 60 nerve cells, responsible for vision. Each of these nerve cells responds only to a signal with a certain intensity.

But for the analysis of optical flows, information coming from both eyes simultaneously is important. This connection is provided by special neurons called “VS cells”. They allow the fly to accurately assess its location in space and flight speed. It appears that the “VS cells” are responsible for sensing and responding to the torque applied to the fly during its flight maneuvers.

Robotics researchers are working to develop robots that can observe environment using digital cameras, study what they see and respond appropriately to changes in the current situation. And communicate and interact with people effectively and safely.

For example, development is already underway on a small flying robot, the position and speed of which will be controlled using a computer system that imitates the vision of a fly.

Ability to see the world in the entire spectrum of its colors and shades - a unique gift of nature to man. The world of colors that our eyes can perceive is bright and amazing. But man is not the only living creature on this planet. Do animals and insects also see objects, colors, night shapes? How do flies or bees see our room, for example, or a flower?

insect eyes

Modern science, with the help of special instruments, has been able to see the world through the eyes of different animals. This discovery became a sensation in its time. It turns out that many of our smaller brothers, and especially insects, see a completely different picture from the one we see. Do flies even see? Yes, but not at all like that, and it turns out that we and flies, and other flying and crawling creatures, seem to live in the same world, but completely different.

It's all about Insects, he is not alone, or rather, not entirely alone. The eye of an insect is a collection of thousands of facets or ommatidia. They look like cone lenses. Each such ommatidia sees a different part of the picture, accessible only to it. How do flies see? The image they observe looks like a picture assembled from a mosaic, or a puzzle.

The visual acuity of insects depends on the number of ommatidia. The most sighted is the dragonfly, it has ommatidia - about 30 thousand. Butterflies are also sighted - about 17 thousand, for comparison: a fly has 4 thousand, a bee has 5. The most visually impaired is the ant, its eye contains only 100 facets.

All-round defense

Another ability of insects that differs from humans is the ability to see all around. The eye-lens is capable of seeing everything at 360 o. Among mammals, the hare has the largest visual angle - 180 degrees. That’s why he’s nicknamed the oblique one, but what to do if there are so many enemies. The lion is not afraid of enemies, and his eyes look at less than 30 degrees of the horizon. In small insects, nature compensated for the lack of growth with the ability to see everyone who creeps up on them. What else is different? visual perception insects, is the speed of picture changes. During a fast flight, they manage to notice everything that people cannot see at such speed. For example, how do flies see TV? If our eyes were like those of a fly or a bee, we would need to spin the film ten times faster. It is almost impossible to catch a fly from behind; it sees the wave of the hand faster than it occurs. A man seems like a slow turtle to an insect, and a tortoise seems like a generally motionless stone.

Colors of rainbow

Almost all insects are color blind. They distinguish colors, but in their own way. Interestingly, the eyes of insects and even some mammals do not perceive red at all or see it as blue or violet. To a bee, red flowers look black. Plants that need bee pollination do not bloom red. Majority bright colors scarlet, pink, orange, burgundy, but not red. Those rare ones that allow themselves a red outfit are pollinated in a different way. This is the relationship in nature. It’s hard to imagine how scientists managed to figure out how flies see the colors of a room, but it turns out that their favorite color is yellow, and blue and green irritate them. Just like that. To have fewer flies in your kitchen, you just need to paint it correctly.

Can flies see in the dark?

Flies, like most flying insects, sleep at night. Yes, yes, they need sleep too. If a fly is constantly driven away and not allowed to sleep for three days, it dies. Flies see poorly in the dark. These are insects with round eyes, but shortsighted. They do not need eyes to find food.

Unlike flies, worker bees see well at night, which allows them to work on the night shift too. At night, the flowers smell more intensely and there are fewer competitors for nectar.

They see well at night, but the undoubted leader in vision in the dark is the American cockroach.

Item Shape

The perception of the shape of an object by different insects is interesting. The specificity is that they may not perceive simple forms at all, which are not necessary for their viability. Bees and butterflies do not see objects simple shapes, especially those who are motionless, but they are attracted by everything that has complex shapes flowers, especially if they move and sway. This explains, in particular, the fact that bees and wasps rarely sting a person standing motionless, and if they do, it is in the area of the lips when he is talking (moving his lips). Flies and some other insects do not perceive a person; they sit on him simply in search of food, which they look for by smell and see with sensors on their paws.

General features of insect vision

Only butterflies can distinguish red color - they pollinate rare flowers such a range.
All eyes have a facet structure, the difference being in the number of ommatidia.
Trichromasia, or the ability to transform colors into three primary colors: violet, green and ultraviolet.
Ability to break and reflect light rays and see the whole picture of the surrounding reality.
The ability to look at pictures that change very quickly.
Insects can navigate by sunlight, so moths flock to the lamp.
Binocular vision helps predators in the insect world accurately determine distances to their prey.