Flies eyes special You might have such experience， when a fly settled on the desktop， you use a hand to capture it， will find that hand is not down， and it has already flew off the "wrong place" This is why， don't fly still long eyes behind not to become? Scientists to fly through the eyes of the study that found the fly's eye is very special， there are 5 3 of them only smaller is described， is feeling of the strength of the brightness， another two for FuYan， each only by many hexagonal visual unit of small This great small eyes all their own systems， independent of the optical system and lead to brain nerve， these little eyes visual nerve can cooperate with each other， can coordinated and be able to work Therefore， flies have not only the eyes speed， height of resolving power， and the orientation of the different feel from video， this also is people use YingPai from behind it is easy to be found a This FuYan has the very high time resolution， it can put the movement of objects into a single continuous lens， and by each small eyes take turns "duty" The eyes of the people is spherical， flies eyes is half of the As the human eye can't fly's eye that turn， flies can see things， want to rely on neck and body rotation， can the eyes toward the Flies eyes no eye socket， not his eyelids no eye， eye the outer layer of the cornea is direct and head surface Look from the outside， flies eye surface (corneal) is smooth level off， if put it under a microscope， people will find， flies by many small eyes is hexagonal structure M Each small hexagonal is a small eyes， scientists call them little In a fly's eyes， has more than 3000 small eyes， a pair of eyes flies there are more than 6000 little Such a small eye by many eyes， called the FuY Flies in the eyes of every small eye has become a system oneself， have the cornea of crystal d imaging system， light sensitive by the visual up of cells of the retina to the brain and to the optic Therefore， every small eyes can see things Scientists have done a test: the flies the cornea stripping down eye for photography lens， on camera under a microscope， and immediately he was as the same as the Scientists are interested in a fly's eye， eye have many flies is amazing If a person's head motionless， eyes can see the scope will not exceed 180 degrees， the body behind the thing can't But， flies eyes can see 350 degrees， you can almost see a circle， only poor back part of skull edge a very narrow a small The human eye can see the visible light， and flies eye but can see see not the people of ultraviolet To see the rapid movement of objects， the human eye is more than a fly's Generally speaking， the human eye with 05 seconds to see the outline of the object， and flies eye as long as 01 seconds will Flies eye or a natural speedometer， can detect their flight speed， so can fast track targets in According to this principle， at present people developed measuring relative to the ground plane speed of electronic device， called "the plane to speed indicator"， and has set up a file in the plane to This instrument structure， is simply: on the fuselage install two mutual into certain angles photoelectric receivers (or in the head， the tail each pack a photoelectric receivers)， which in turn receive the same point on the ground of the light According to two receiver receive signals shift and measurement of the flying height at that time， and by the electronic computer， can indicate the instrument relative to the ground plane flight
