Animals with incredible eyes
According to scientists, the eyes have evolved for about 540 million years ago, it was the usual authority to detect light. Today the vision is extremely important for many animals, including for people, it's very complicated and it was diverse.
Take a look at some of the strangest and most incredible eyes in the animal kingdom.
We all know that the pupils are round, because the round pupils - this is what we see most often (in humans), but it can not be attributed to the goats (and most other animals with hooves), in which the horizontal slots that accept the expansion of a rectangular shape. This gives the opportunity to see the goats at 320-340 degrees around itself, that is, they see almost everything without having to turning your head (for comparison: a person sees at 160-210 degrees).
Consequently, animals with rectangular eyes can see better at night because of the large pupils, which is very narrow, as close to the purpose of restricting access of light during the day. It is interesting that of the octopus rectangular pupils.
Trilobites were one of the most successful groups of animals of all ages, which flourished for nearly 300 million years, long before the earth began to inhabit the dinosaurs. Although some species were eyeless, most have complex eyes like the eyes of insects.
The strange fact about trilobites eyes is that the shell of the eyes was made of calcite crystals of inorganic (mineral, which is the main component of limestone and chalk). In pure form, transparent calcite, which is suitable as a material for the lens of the eye.
These crystal eyes are unique feature trilobite eyes because modern invertebrate composed of chitin organic material. Thanks to its unusual composition, trilobite eyes were very hard and could not on something to focus, instead, trilobites adjusted the focus with the inner eye of the mechanism, which not only resolves any potential problems associated with the mineral lens, but also gave the trilobites are so good vision that they can hold in focus at the same time as the long and near objects.
If this does not seem to you quite strange, it is worth noting that some trilobites eyes were located at the end of the extended age, while others eyes were overhanging "bandage" which protects them from the bright sunlight. Since the surface of the eye have been of calcite, the fossils are very well preserved, so the vision of trilobites known more than any other historical beings in general.
Tarsier - a small (the size of a squirrel) nocturnal primate that lives in the tropical forests of Southeast Asia. It is the only exclusively carnivorous primate in the world, feeding on lizards and insects. There are even cases when they catch birds during their flight. The most remarkable feature of them are undoubtedly huge eyes, which are the largest among all mammals in relation to body size.
If human eyes were the same proportions as the eyes tarsiers, they would be the size of a grapefruit. These huge eyes sit deep in the skull, and can not turn in their sockets. To compensate for this tarsiers have a very flexible neck and head can rotate 180 degrees, as well as a night owl, to find potential victims.
Each of his eyes weighs more than the entire brain and vision in this animal is very keen. Moreover, tarsiers have excellent night vision, which suggests that they are able to discern even ultraviolet light. On the other hand, it seems to have a very poorly developed color vision, as is the case with many nocturnal animals (including with domestic cats, and owls).
A unique pet chameleon
Chameleon is known for its characteristic color change. This helps him to communicate and demonstrate their intentions and sentiments of other chameleons (only a few of their species use color change to camouflage). These lizards are also very unusual eyes, their lids are merged and cover virtually all of the eyeball, except for a small opening through which the pupil can see.
Each eye can move independently of the other, so the chameleon can simultaneously scan production and a potential threat. It also says that the chameleon has a 360-degree field of view.
When the chameleon sees potential victim (this is usually insects, although the largest species feed on mice and other small vertebrates) it aimed both eyes, so it achieves the effect of stereoscopic vision, which is very important in this context, if consider that a chameleon captures prey, "vystrelivaya" language at high speed, and is a technique that requires precision in the distance and depth perception. Chameleons have very keen eyesight, they are able to see the insect at a distance of several meters, and as tarsiers, they can see ultraviolet rays.
Amazing insect dragonfly
Dragonfly, which is perhaps the most formidable air hunter among insects, also has one of the most amazing eyes in the animal kingdom. They are so large that they cover almost the entire head, giving it the look of the helmet, and giving an overview of 360 degrees.
These eyes consist of 30,000 visual elements called ommatidia, each of which contains the lens and a number of light-sensitive cells. Their eyesight is excellent, they distinguish a wide range of colors and polarized light, they are particularly sensitive to motion, so it is quickly recognize any potential prey or enemy.
Some species of dragonflies that "hunt" in the evening, have a perfect vision in low light conditions, while we, the people, barely able to see anything. Moreover, dragonflies have three small eyes that can detect movement faster than do larger ones. These eyes quickly send visual information to the central nervous system of the dragonfly, which allows it to react in a split second. Perhaps precisely because of this feature, you can explain the origin of insects unique acrobatic skills. Despite the fact that dragonflies - are not the only insects that have additional small eyes (some wasps and flies as they are), dragonflies are the most developed.
Satanic gecko (his middle name) has the eyes of a pretty surreal type, their pupils are vertical and have a number of holes, which dilate at night, allowing these lizards take as much light as possible. The eyes are also much more light-sensitive cells than the human eye, it gives the animal the ability to detect objects and even see colors at night.
That you understand how really amazing night vision gecko should just note that if the cats and sharks can be seen in six and ten times better than the people that listohvostye geckos and other nocturnal species of geckos see up to 350 times better, what we in the dim light.
These animals also have a strange, intricate patterns on the eyes, making them camouflage. These lizards have eyelids, and eyes protected by a transparent cover, which geckos purified by their language.
Not to be confused with the more famous, but smaller in size the giant squid. The colossal squid is the largest invertebrate known to science, it also has one of the largest eyes in the animal kingdom. Each squid eye reaches a diameter of 30 cm, it may be larger than a plate, and lens size with his eyes orange. These huge eyes allow the squid to see in dim light, which is very useful for an animal that spends most of his life hunting at depths greater than 2000 meters.
It should be noted that until now had only caught a colossal squid - youth, adult same individual can grow up to 15 meters in length. These giants eye even more. Unlike giant squid, the squid has enormous stereopsis, and has an excellent ability to accurately estimate the distance. Even more amazing feature is that each eye has a built-in "spotlight", the body that can produce as much light as you need squid to see their prey in the dark.
Found in Mexico, Central America and South America, this fish, up to 32 cm, usually lives in fresh or salt water (although repeatedly noticed it and on the coast). It feeds mainly on insects, so most of the time is spent swimming at the surface.
Despite its name, Four-in fish is actually two eyes, each divided part of the flesh, and all four "parts" have their own pupils. This strange "device" allows chetyrehglazogo fish is excellent to see both above and below the waterline, scanning prey and predators.
The upper half of the eyeball is adapted to what to see in the air, while the lower half is used for underwater vision. Although both halves of the eyes use the same lens, the shell thickness different in upper and lower parts, and therefore the behavior of fish in the air and in the water different.
This means that when the four eyes of the fish are completely submerged in water, the upper halves of the eye are not in focus. Fortunately, the fish spends most of his life near the water surface and sinks is very rare with the only aim to protect the upper halves of the eyes from dehydration.
These small but fascinating creatures most often found in the jungles of Southeast Asia and Africa, but there are some species that are found in Europe and North America. They got their name from the long, similar to the stems formations located on the sides of the head, at the end of which the eye.
The male flies tend to have longer stems and large, than women. In turn, the females prefer males with the longest eyestalks. Males often during the mating season, facing each other and are measured by their stems, the winner is the one with the longest stem.
Furthermore, the male flies stebleglazoy possesses extraordinary abilities that help him to increase in size and eye stalks: they swallow air through the mouth and "push" it through ducts in the eye stalks. Basically they do it during the mating period.
This deep-water fish, which has one of the most bizarre ocular structures among all known. Each eye has a lateral swelling called diverticulum, which is separated from the main eye wall. While the bulk of the eye has a shell and features that are similar to the functions of eyes of other animals, diverticulum has a curved composite "mirror", consisting of several layers of crystals.
This "mirror" collects much more light than normal eyes. Diverticulum reflects light and focuses it on the retina, allowing the fish to see how the top and bottom at the same time.
This fish is the only known vertebrates that uses a mirror structure of the eye, just to see, that is how conventional lenses. It can be found in different parts of the world, but rarely get to see, because most of his life holds fish at a depth of 1000-2000 meters. They feed on small crustaceans and plankton, and their body length of about 18 cm.
The spiders - ogres
These spiders are widely known fact that they have a large number of eye (although this number varies greatly among the different species from 2 to 8). Face Spider - ogres has six eyes, but it looks as if he has them only two, because the average pair of much more than any other.
All of this created for the convenience of night life. With a little scary-looking face, spiders have excellent night vision not only through the eyes, but also thanks to the extremely sensitive layer of cells that covers them.
This membrane is so sensitive that it self-destructs at dawn and at night there is a new. Face of this spider looks unusual, because it is beautiful to see at night, but it lacks reflective membrane that helps other spiders (and other predators) to see in low light conditions. Scientists believe that this spider actually have night vision that is better than cats, sharks and even an owl (which can be seen at night up to 100 times better than humans).
Crayfish - mantis
Finally, we arrived at the animal, which has the strangest and most wonderful eyes in the world. Crayfish - mantis - this is not the shrimp and arthropods belonging to a different species of crustaceans from the order mantis. They are known for their aggressive and dangerous weapon (they have a very strong and sharp claws, which can easily cut the human finger, or even smash the glass aquarium with a single stroke). Crayfish - Mantis - a voracious predators that live mainly in tropical waters.
Their eyes are very complex in structure, but similar to a dragonfly's eyes. They also possess ommatidia (about 10,000 per eye), however, cancers - mantid each ommatidia certain portion has a certain function. For example, some of them are used for the detection light, the other to determine the colors, etc. In cancers -.. Mantid much better developed color vision than in humans, their eyes have 12 types of color receptors, whereas in humans it only 3. Moreover, they have ultraviolet, infrared and polarized vision, thus their vision is the most difficult among all animals. The eyes are located at the end of the particular stem and can move independently of each other, rotating by 70 degrees. Interestingly, the visual information is processed by the eyes, but not the brain.
Even more strange is the fact that each eye cancer - mantis is divided into three parts, which allows arthropods see objects from three different viewpoints of the same eye. In other words, each eye has a "trinocular vision" and full of depth perception, which means that if the cancer will lose the eye, remaining eye will still be able to judge depth and distance as well as people with their two eyes.
Scientists are just beginning to understand the secrets of view, just how has cancer - a mantis, so at the moment we can only imagine how the world sees the creature.