How many frames per second does a fly see and how many eyes does it have

All people know that it is very difficult to catch or swat a fly: it sees very well and instantly reacts to any movements, taking off upwards. The answer lies in the unique vision of this insect. The answer to the question of how many eyes a fly has will help to understand the reason for its elusiveness.

Device of visual organs

The domestic or ordinary fly has a black-gray color of the body up to 1 cm in length and a slightly yellowish belly, 2 pairs of gray wings and a head with large eyes.It belongs to the most ancient inhabitants of the planet, as evidenced by the data of archaeologists who discovered specimens dating back 145 million years.

When examining a fly's head under a microscope, one can see that it has very original volumetric eyes, located on both sides. As seen in the photo of the fly's eyes, they visually resemble a mosaic made up of 6-sided structural units, called facets or ommatidia, similar to the structure of honeycombs. Translated from the French word "fasette" means the face. Due to this, eyes are called faceted.

How to understand what a fly sees in comparison with a person whose vision is binocular, that is, it is made up of two pictures that see 2 eyes? In insects, the visual apparatus is more complex: each eye consists of 4 thousand facets, showing a small part of the visible image. Therefore, the formation of a general picture of the external world takes place according to the principle of “collecting puzzles,” which allows us to speak about the unique structure of the brain of flies, capable of processing more than 100 frames of images per second.

On a note!

Faceted vision is not only in flies, but also in other insects: bees have 5 thousand.17 thousand for facets, but 30 thousand ommatidia for dragonfly record holders.

As the fly sees

Fly vision apparatus

Such a device of the visual organs does not allow the fly to concentrate on a particular object or object, but shows a general picture of the entire surrounding space, which allows you to quickly notice the danger. The viewing angle of each eye is 180 °, which together amounts to 360 °, that is, the type of view is panoramic.

Thanks to this eye structure, the fly perfectly surveys everything around, including seeing a person who is trying to sneak up behind him. Control of the whole surrounding space provides her with 100% defense against all troubles, including from people who are going to kill the fly.

In addition to the 2 main ones, flies have 3 more ordinary eyes located on the forehead in the intervals between facets. These bodies allow them to view nearby objects more clearly for recognition and instantaneous response.

Interesting!

Summarizing all the data, it can be stated that the vision of a fly is represented by 5 eyes: 2 faceted - to control the surrounding space and 3 simple - to adjust the sharpness and recognition of objects.

Features of visual abilities flies

The sight of a common fly has many more interesting features:

• primary colors and their shades of a fly are perfectly distinguished, and they are also capable of distinguishing ultraviolet rays;
• they see absolutely nothing in darkness and therefore sleep at night;
• However, some colors from the whole palette are caught a little differently, therefore they are conditionally considered to be color-blind;
• the facet device of the eyes allows you to capture all at the same time at the top, bottom, left, right and front and allows you to quickly respond to the approaching danger;
• eyes of a fly can only distinguish small objects, for example, an approach of a hand, but they do not perceive a large human figure or furniture in a room;
• in males, the faceted eyes are closer to each other than females with a wider forehead;

Interesting!

The fact how many frames per second a fly sees is also evidence of visual acuity. For comparison, the exact figures: a person perceives only 16, and a fly - 250-300 frames per second, which helps her to perfectly navigate at a fast speed in flight.

Atrial characteristics

Eyes fly

There is an indicator of visual abilities, which is associated with the flicker frequency of the image, i.e., its lowest limit, at which the light is fixed as a constant source of illumination. It is called CFF - critical flicker-fusion frequency. Its value indicates how quickly the eyes of an animal are able to update the image and process visual information.

A person is able to catch the flicker frequency of 60 Hz, i.e., updating the image 60 times per second, which is followed when displaying visual information on a television screen. For mammals (dogs, cats), this critical value is 80 Hz, which is why they usually do not like watching TV.

The higher the flicker frequency value, the more biological advantages the animal has. Therefore, for insects in which this value reaches 250 Hz, this is manifested in the possibility of a faster response to danger. Indeed, for a person approaching "prey" with a newspaper in his hands with the intention to kill her, the movement seems to be fast, but the unique structure of the eye room fly allows her to catch even instantaneous movements, as if in slow motion.

According to the biologist K.Gili, such a high critical frequency of blinking in flies due to their small size and fast metabolism.

Interesting!

The difference in CFF for different species of vertebrate animals is as follows: the smallest 14 Hz - in eels and turtles, 45 - in reptiles, 60 each in people and sharks, in birds and dogs - 80, and in gophers - 120.

The analysis of visual abilities allows us to understand that the world through the eyes of a fly looks like a complex system of a large number of pictures, by analogy with small video cameras, each of which transmits information to an insect about a small part of the surrounding space. The combined image allows flies at a glance, keep a visual "all-round defense" and instantly react to the approach of enemies. Researches of scientists of such visual abilities of insects made it possible to develop flying robots, in which computer systems control their position in flight, imitating the sight of flies.