The eyes are the organs of the eye system. They offer visibility to organisms, access to visual details and process, and enable the use of various functions of independent photo-reactive Photoreactions. Eyes recognize light and turn them into neurons into electrochemical impulses. With higher organisms the eye is a complete optical system, the light of the environment gathers its intensity of adjustable length, performs a controlled lens system to produce the image and converts the image into electrical signals into series, and sends these signals through complex nerve pathways in the brain that connect to the eye through optic nerve with the cornea of the eye and other parts of the brain. Eye shades have ten essentially different shapes, and 96% of species have a complex optical system. Crete, kites and images of arthropods solve their eyes.
2. Vision Of Field
Visual acuity and poor visibility. Visual acuity is a number that exhibits sharpness or clarity. Visual focus 20/70 refers to a person with 20/70 vision, which is a 20 foot eye chart to see what a person can see on unlimited (or 20/20) to 70 feet away.
2.1 Field of view
Blurred fields next to the human eye (measured from the point of attachment, i.e. the point where the sight is directed) varies depending on the anatomical structure of the face, but is usually around 30 ° higher (upper limit at the end), 45 ° C to the nose, 70 ° lower 100 ° (towards the temple).
For both eyes, the total binocular field is 135 ° vertically and 200 ° horizontally. If the iris and pupil of the page is considered a high angle, they can still be seen by the viewer indicating that this person is in peripheral vision.
2.2 Dynamic range
The retina has a static contrast ratio of around 100: 1 (around 6.5 f-stops). When the eyes move quickly to reach the goal (saccade), it again adjusts the exposure by adjusting the aperture, the pupil size is adjustable. The initial dark correction occurs for about forty seconds, a deeper, uninterrupted darkness; Complete adaptation by adapting the retinal rubber photoreceptor is completed within 30 minutes.
The process is nonlinear and versatile, therefore the process of obfuscation must be resumed during the duration of the plan. Any adjustment depends on good blood flow. Therefore, the dark adaptation can be prevented due to retinal disease, poor circulation and high altitude exposure.
2.3 Eye movements
The visual system of the human brain is too slow to process information when the image transmits the retina in a few seconds per second. To see the movement, the brain has to compensate for the movement of the head by turning the eyes. Animals with eyes on the forehead have a small area of the retina with very high visual acuity, fovea centralis. Includes two angles for people.
To get a clear picture of the world, the brain has to turn the eyes so that the image of the visual object fits into the hole. Inaccurate eye movement can significantly worsen vision .
3. Types of eyes
There are ten different ways to place the eye. In fact, in nature there is any technological process that detects an optical image that is commonly used by humans, with the exception of zoom and Fresnel lenses. The types of Oye can be divided into “straight eyes” with concave photoreceptor surfaces and “complicated eyes” that contain many individual lenses that are on a convex surface. Note that “straight” does not reduce complexity or sharpness. In fact, each type of eye can be adapted to almost any behavior or environment.
3.1 Non-compound eyes
Simple eyes are everywhere, and lumbar vertebrae evolve in vertebrates, cephalopods, stomachs, crustaceans and ankles for at least seven occasions.
3.1.1 Pit eyes
Pit-Eyes, also called Stamma, is an ocular point that can be placed in the cavity to reduce the angle of the eye so that the body can extract the angle of inclination of the light. These basic forms, found in about 85% of the fila, were probably precursors to advanced “straight eyes”.
They are small and form about 100 cells, covering about 100 μm. The direction can be improved by reducing the size of the hole by introducing a reflective layer on the receiver’s cells or filling the gap with fuzzy material.
3.1.2 Spherical lens eye
The resolution of eye-scaring can be significantly improved by incorporating a material with a higher refractive index to create a lens that can significantly reduce the perceived radiation, thus increasing the available resolution. The most common form of some bridges and annular rings is a lens with a refractive index. A more clear image can be obtained with materials with a high refractive index that reduces the edges.
It reduces the focal length, providing a vivid picture. It also provides a larger aperture for a certain brightness, allowing more light to enter the lens; and a smooth lens that reduces spherical aberration. Such a non-uniform lens is required at a focal length of about 4 times greater than the lens radius with a radius of up to 2.5.
3.1.3 Multiple lenses
Some marine organisms contain more than one lens, for example Copapod Pontella has three. Outside there is a parabolic surface that neutralizes the effects of spherical aberration while creating a sharp image. Another copywriter, Copilia, has two glasses that are set up as a telescope. Such measures are rare and poorly understood, but there are alternative projects.
3.2 Compound eyes
A complex eye can consist of thousands of individual photoreceptor units or symbols. The observed image is at the expense of a large number of ommathes, with convex surfaces in slightly different directions. Complex eyes have a very wide viewing angle compared to ordinary eyes and can detect rapid movements and in some cases polarization of light.
Because individual lenses are so small, diffraction effects limit the possible level of resolution. This can only be solved by increasing the size and number of lenses. To see an expression similar to our simple eyes, people need very large, complex eyes with a radius of about 11 meters.
3.2.1 Apposition eyes
Appeal eyes are the most common type of eye and are probably a kind of complex ancestral eyes. They can be detected in all arthropod groups, although they have developed more than once in these strains. Some nipples and sinks also have eyes of apoptosis.
They also belong to the Limulus, horseshoe crabs, and there are suggestions that another Chelikate created them straight into the eyes by reducing the composite base.
The ciliary body is located in a horizontal cross-section of triangular shape and is covered with a double layer, the ciliary epithelium. The inner layer is clear and contains enamel and is permanently removed from the retinal nerve tissue. The outer layer is colored, continuous from retinal pigment epithelium and Dilatatormuskels cell formation.
The glass mass is a transparent, colorless, jelly-like mass that fills the space between the lens and the retina in the posterior surface of the eye. It is produced by some retinal cells.
4. Color perception
“Color vision is the body’s ability to separate light from various spectral properties.” All organisms only in a small range of the electromagnetic spectrum, depending on the nature of the form, however, in most cases with a wavelength between 400 and 700 nm.
It is a relatively small part of the electromagnetic spectrum, probably due to the development of underwater parts of the body of water, but without the EM spectrum, two small windows and terrestrial animals has been an evolutionary pressure to expand.
The most sensitive rhodopsin pigment has a maximum response of 500 nm. Small changes in the genes that make up the code of this protein, the maximum response can change to several nm. Pigments on the lenses can also filter the emitted light and cause the greatest response to changes. Many organisms can not distinguish colors.
5. Eye Pigmentation
The pigment molecules used in the eye are different, but they can be used to determine the evolutionary distance between the different groups. They can also be useful in determining which are closely related – although there are also convergence problems. Optics are pigments used in photorexia. Other pigments, such as melanin, are used to protect photoreceptor cells from leakage on the light side.
The group of optybody proteins has developed for a long time before the animal is the last common ancestor and has been increasingly diversified ever since. C-opinions are also found in some of the twelve invertebrates, for example in the eyes of mussels; But the side eyes, which are probably the stems in this group, always use R-op as soon as the eyes are formed.
6. Eye color
The eye color is multi-phenotypic in nature and is determined by two different factors, iris pigmentation and frequency dependence on light scattering through the opaque iris root medium.
People pigmentation iris from light brown to black color varies depending on the concentration of melanin in the pigment epithelial epithelium (at the back of the diaphragm), the content of iris stroma and the density of the iris cells. Stromes Blue and green and hazel eyes look is the scattering of light in the strand Tyndall, a phenomenon similar to the one that explains the heavens, Rayleigh’s result of blue.
7. Genetic determination Of Eye Vision
Eye color is an inherited trait affected by more than one gene. These genes look for associations with minor changes in the genes themselves and in neighboring genes. These changes are called single nucleotide polymorphisms or SNPs. The true number of genes that contribute to eye color is unknown at this time, but candidates are likely.
A study conducted in Rotterdam (2009) showed that only six SNP eye colors can be predicted with more than 90% accuracy in brown and blue. There is evidence that up to 16 different genes that are responsible for the color of the human eye, but the two most important genes associated with changing the eye color is oca2 and hec2. Both are chromosomes.
8. Changes in eye color
Most newborns in Europe have bright eyes. When a child develops, melanocytes slowly produce melanin. Because melanocyte cells constantly produce pigment, the eye color can in theory be changed. Eye color in adults usually ranges from 3 to 6 months, but may be later. When the child Iris in the side view with only light without reflection from the back iris, it is possible to determine the presence or absence of low levels of melanin.
The blue hole of this method of observation, when the child grows, remains blue. An illusion that looks like gold has a certain melanin, even at such a young age and can change from blue to green or brown when the child grows up. Changes Eye color of early childhood, puberty, pregnancy, and sometimes after a severe injury, there is no reason for the logical argument that some of the eye can change as a result of chemical reactions and hormonal changes in the body or .
Eye is an important organ with an innate immune system, eliminating allergens or infectious substances, secreting secretions, eyelashes, etc. Eye care is today devoting much attention to environmental pollution and resistant pathogens. Increased radiation, lighting, digital devices and LEDs, etc.
Reduced the mechanism of action of muscles that act as eyes and secrete tears. That is why people are very sensitive to many viral, bacterial and fungal infections. Higher levels of ultraviolet radiation and changes