Whether you know that?. The surprising facts about sight of animals
Having got acquainted with features of sight at dumb animals, it is difficult not to exclaim: “ Where on inventions the nature is liberal! “. However, let`s understand one after another.
The number of visual bodies and their arrangement
the Scallop has about one hundred eyes on edge of a sink, with their help the mollusk traces predators. At a starfish which also concerns to those photosensitive cages are located on extremities (“ beams “) and at many crabs of an eye are arranged on “ small stalks “.
Some species of scorpions have up to 12 eyes, and many spiders - on eight, the well-known New Zealand lizard of a tuatar who is considered as the contemporary of dinosaurs, and is called - “ trekhglazy “. Her third eye is in a forehead!
“ External data “ and the internal device
the Huge squid possesses eyes with a diameter up to 25 cm, in each of them is available to 1 billion photoreceptors. Shark too big-eyed being: diameter “ eyes “ at it - to 12,5 cm, and some of types are felt also a skull through a special shishkovidny outgrowth.
Diameter of an eagle eye makes 35 mm. At an octopus as it was already told, the pupil has square shape and is supplied 20 million photoreceptors. In a signature stamp eye retina their one million on square millimeter, i.e. five times is more, than at the person.
Unreliable large representatives of fauna have the difficult device of eyes. For example, at bees about 5,5 thousand tiny lenses in each eye, and at flies - about 3000. And here aquarian Anableps microlepis (“ chetyrekhglazy fish “) actually has only their couple, but each eye is divided into segments, one of which is intended to see in air, another - in water.
It is curious that the retina of a dolphin has similar double control too. To a penguin the flat cornea of an eye allows to see in water without distortions. Snakes have no a century, and their eyes are constantly closed by a transparent elastic membrane. And an eye of a camel is arranged so that the small mote will not even get to it: strong bones at the edges of eye-sockets - protection against mechanical damages and sunshine, and eyelashes possess ability to be weaved and to automatically close an eye at the moment of danger.
Sharpness and visibility of sight Even those who are considered as the immediate genetic family of the person - monkeys - see
three times better it. And not only they, certainly. The eagle, for example, too has three times more sharp-sighted sight, than “ tsar of the nature “. The falcon is capable to make out the purpose of 10 cm from distance of 1,5 km, and and at great speed keeps image sharpness of objects. The signature stamp distinguishes small rodents from distance to 5 kilometers, and the butterfly of Colias can distinguish image elements in 30 microns, overtaking the person more than three times.
At a fly - only present! - speed of change of images makes 300 frames per second, i.e. it surpasses similar ability of the person by 5 - 6 times. And the cockroach notices the movement at a size of 0,0002 mm.
Deep-water fishes, as we know, can see in total darkness, and all because density of placement of sticks in a retina at them reaches 25 million / sq. mm that in 100 times more, than at the person. Cats too perfectly see in darkness because their pupil is capable to extend to 14 millimeters. And dogs in the dark see three times better, than we.
Chameleons and sea horses are able to look in two directions at once, this surprising ability they are obliged to the fact that their eyes move independently from each other. A champion in panoramic sight is the bird a woodcock which has it almost circular! At a pigeon the viewing angle makes 340 degrees, at a horse with the raised head sight approaches spherical too. At dogs visibility on average 240 - 250 degrees that on 60 - 70 units exceeds the similar opportunities inherent in people.
The dream of an omniscience accompanied mankind since the most ancient times. For example, Greeks had stooky Argus. And Buddha? And Shiva? But the animal kingdom as we see, often advances this dream...