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Sight of the fish

The most important body of a fish is the body of sight - an eye. A structure and opportunities of an eye of fishes are adapted for a way of life in water elements. For example, the eye of a catfish and grig in comparison with the perfect eye of a trout, chariusa, pikes and other fishes using sight at hunting, has only minor value.

The crystalline lens of an eye of a fish in comparison with a crystalline lens of a human eye firm also is not capable to change the form. It is in a quiet condition close to a cornea and allows a fish to see up to distance of 5 m. At a sight at greater distance a crystalline lens departs from a cornea and by means of chord comes nearer to a retina. Thus the fish can see on distance up to 15 m. the Back part of a retina by means of special cells - sticks and колбочек perceives color. Sticks allow to see in twilight, bulb perceive a daylight.

On size of an eye concerning a head of a fish we can judge ability to see world around and about visual acuity of fishes.

Sight is the important body because allows them to look out for extraction for fishes, to notice the enemy, to disappear from it, to be guided in space, to define both the form and size of subjects, and distance up to them, and to distinguish their color. Fishes can distinguish and colors, approximately in the same range, as the person. In comparison with the person, however, they perceive also short-wave area of a spectrum which the person as color does not perceive.

On sight in water influences more factors, than sight in an atmosphere. It, for example, such factors

Rays of light extend in air more quickly, than in water, as water - more dense environment. Therefore the ray of light, passing under the certain corner from one environment in another, refracts. It should be understood, if we throw a front sight directly above a fish because actually the fish is closer, than it seems to us.

Light beams do not refract, if they pass from air in water of perpendicularly surface of water. Therefore at a sight from above we see a fish precisely there where it is actually. Because of this refraction of light and the fish sees subjects above water so as-as if looks through a round window. The subjects laying in space, limited by a field of vision of a fish, appear at edges of this window while the subjects laying directly above a fish, are in its middle.

The fish sees above itself a light cone in which observes, for example, insects, take away water on its surface, but the fisherman costing on coast, it already sees perverted.

Subjects which are under a fish, it sees not distinctly, but is exact there where they lay actually.

Subjects which are in a water column before a fish, or above it, the fish sees most distinctly.

As eyes at a fish are located on each side heads, the fish sees not only in small space ahead, but also behind and sideways. For this reason it is necessary to offer a fish a front sight in its visual cone.

From the resulted data on visual perception of fishes follows, that on a surface of water the fish perceives most distinctly changes on a superficial film the waters made by a body and legs of an artificial front sight; when the front sight вплывает in a light cone, a fish perceives simultaneously and color of its separate parts. Having passed through a light cone, the front sight gradually passes in area of back light and the fish perceives already only it silhouette.

The visual perception of fishes is influenced also with other factors, such as current of water, the direction of refraction of light, cleanliness of water, etc. On silent waters of a fish, obviously, perceive all details of a front sight, especially color and a transparency of a body. Our success depends on accuracy of imitation of alive insects, and special value gets a transparency of a body.