Eye Of Segelreisen, Events & Incentives, Vollcharter, Tagesfahrten, Hafenfeste
Mrs Colombo Svevo's experience has in fact enabled her to encapsulate it perfectly: at the moment the report is again in the eye of the storm because we cannot. Segelschiffsreisen zum Mitsegeln auf dem Windjammer Eye of the Wind. Nord- und Ostsee, Mittelmeer, Karibik und Transatlantik. Hafenfeste & Charterfahrten. Die Eye of the Wind ist ein Juwel unter den letzten original erhaltenen Großseglern unserer Zeit. Informationen über die Geschichte, Daten und Bilder finden Sie. Eye of the Tiger erschien als drittes Album von Survivor und war das erfolgreichste Album ihrer Karriere. Inhaltsverzeichnis. 1 Geschichte; 2 Titel; 3 Andere. Eye of the Tiger ist ein Lied der Band Survivor, das von Frankie Sullivan und Jim Peterik für den Film Rocky III – Das Auge des Tigers () geschrieben wurde.
EYE OF THE WORLD (Wheel of Time) | Jordan, Robert | ISBN: | Kostenloser Versand für alle Bücher mit Versand und Verkauf duch Amazon. Fotografie · Portfolio-Überblick · Best of – · Best of – · Best of – · Audiovision · Workshops · Thematische Übersicht · Termin-Übersicht; Termine. Mrs Colombo Svevo's experience has in fact enabled her to encapsulate it perfectly: at the moment the report is again in the eye of the storm because we cannot. EYE OF THE WORLD (Wheel of Time) | Jordan, Robert | ISBN: | Kostenloser Versand für alle Bücher mit Versand und Verkauf duch Amazon. The Eye of the I: From Which Nothing Is Hidden | Hawkins, David R. | ISBN: | Kostenloser Versand für alle Bücher mit Versand und Verkauf. Scientific Photography, especially scanning electron microscopy and microphotography since Raster-Elektronenmikroskopie und Mikrofotografie seit. Fotografie · Portfolio-Überblick · Best of – · Best of – · Best of – · Audiovision · Workshops · Thematische Übersicht · Termin-Übersicht; Termine.
Photoreception is phylogenetically very old, with various theories of phylogenesis. This is based upon the shared genetic features of all eyes; that is, all modern eyes, varied as they are, have their origins in a proto-eye believed to have evolved some million years ago,    and the PAX6 gene is considered a key factor in this.
The majority of the advancements in early eyes are believed to have taken only a few million years to develop, since the first predator to gain true imaging would have touched off an "arms race"  among all species that did not flee the photopic environment.
Prey animals and competing predators alike would be at a distinct disadvantage without such capabilities and would be less likely to survive and reproduce.
Hence multiple eye types and subtypes developed in parallel except those of groups, such as the vertebrates, that were only forced into the photopic environment at a late stage.
Eyes in various animals show adaptation to their requirements. For example, the eye of a bird of prey has much greater visual acuity than a human eye , and in some cases can detect ultraviolet radiation.
The different forms of eye in, for example, vertebrates and molluscs are examples of parallel evolution , despite their distant common ancestry. Phenotypic convergence of the geometry of cephalopod and most vertebrate eyes creates the impression that the vertebrate eye evolved from an imaging cephalopod eye , but this is not the case, as the reversed roles of their respective ciliary and rhabdomeric opsin classes  and different lens crystallins show.
The very earliest "eyes", called eye-spots, were simple patches of photoreceptor protein in unicellular animals.
In multicellular beings, multicellular eyespots evolved, physically similar to the receptor patches for taste and smell.
These eyespots could only sense ambient brightness: they could distinguish light and dark, but not the direction of the light source.
Through gradual change, the eye-spots of species living in well-lit environments depressed into a shallow "cup" shape.
The ability to slightly discriminate directional brightness was achieved by using the angle at which the light hit certain cells to identify the source.
The pit deepened over time, the opening diminished in size, and the number of photoreceptor cells increased, forming an effective pinhole camera that was capable of dimly distinguishing shapes.
This would have led to a somewhat different evolutionary trajectory for the vertebrate eye than for other animal eyes. The thin overgrowth of transparent cells over the eye's aperture, originally formed to prevent damage to the eyespot, allowed the segregated contents of the eye chamber to specialise into a transparent humour that optimised colour filtering, blocked harmful radiation, improved the eye's refractive index , and allowed functionality outside of water.
The transparent protective cells eventually split into two layers, with circulatory fluid in between that allowed wider viewing angles and greater imaging resolution, and the thickness of the transparent layer gradually increased, in most species with the transparent crystallin protein.
The gap between tissue layers naturally formed a biconvex shape, an optimally ideal structure for a normal refractive index. Independently, a transparent layer and a nontransparent layer split forward from the lens: the cornea and iris.
Separation of the forward layer again formed a humour, the aqueous humour. This increased refractive power and again eased circulatory problems.
Formation of a nontransparent ring allowed more blood vessels, more circulation, and larger eye sizes. Eyes are generally adapted to the environment and life requirements of the organism which bears them.
For instance, the distribution of photoreceptors tends to match the area in which the highest acuity is required, with horizon-scanning organisms, such as those that live on the African plains, having a horizontal line of high-density ganglia, while tree-dwelling creatures which require good all-round vision tend to have a symmetrical distribution of ganglia, with acuity decreasing outwards from the centre.
Of course, for most eye types, it is impossible to diverge from a spherical form, so only the density of optical receptors can be altered. In organisms with compound eyes, it is the number of ommatidia rather than ganglia that reflects the region of highest data acquisition.
An extension of this concept is that the eyes of predators typically have a zone of very acute vision at their centre, to assist in the identification of prey.
The hyperiid amphipods are deep water animals that feed on organisms above them. Their eyes are almost divided into two, with the upper region thought to be involved in detecting the silhouettes of potential prey—or predators—against the faint light of the sky above.
Accordingly, deeper water hyperiids, where the light against which the silhouettes must be compared is dimmer, have larger "upper-eyes", and may lose the lower portion of their eyes altogether.
Acuity is higher among male organisms that mate in mid-air, as they need to be able to spot and assess potential mates against a very large backdrop.
It is not only the shape of the eye that may be affected by lifestyle. Eyes can be the most visible parts of organisms, and this can act as a pressure on organisms to have more transparent eyes at the cost of function.
Eyes may be mounted on stalks to provide better all-round vision, by lifting them above an organism's carapace; this also allows them to track predators or prey without moving the head.
Visual acuity , or resolving power, is "the ability to distinguish fine detail" and is the property of cone cells. For example, if each pattern is 1.
The highest such number that the eye can resolve as stripes, or distinguish from a grey block, is then the measurement of visual acuity of the eye.
For a human eye with excellent acuity, the maximum theoretical resolution is 50 CPD  1. A rat can resolve only about 1 to 2 CPD. However, in the compound eye, the resolution is related to the size of individual ommatidia and the distance between neighbouring ommatidia.
Physically these cannot be reduced in size to achieve the acuity seen with single lensed eyes as in mammals. Compound eyes have a much lower acuity than vertebrate eyes.
In primates, geckos, and other organisms, these take the form of cone cells , from which the more sensitive rod cells evolved. Most organisms with colour vision can detect ultraviolet light.
This high energy light can be damaging to receptor cells. With a few exceptions snakes, placental mammals , most organisms avoid these effects by having absorbent oil droplets around their cone cells.
The alternative, developed by organisms that had lost these oil droplets in the course of evolution, is to make the lens impervious to UV light—this precludes the possibility of any UV light being detected, as it does not even reach the retina.
The retina contains two major types of light-sensitive photoreceptor cells used for vision: the rods and the cones. Rods cannot distinguish colours, but are responsible for low-light scotopic monochrome black-and-white vision; they work well in dim light as they contain a pigment, rhodopsin visual purple , which is sensitive at low light intensity, but saturates at higher photopic intensities.
Rods are distributed throughout the retina but there are none at the fovea and none at the blind spot. Rod density is greater in the peripheral retina than in the central retina.
Cones are responsible for colour vision. They require brighter light to function than rods require. In humans, there are three types of cones, maximally sensitive to long-wavelength, medium-wavelength, and short-wavelength light often referred to as red, green, and blue, respectively, though the sensitivity peaks are not actually at these colours.
The colour seen is the combined effect of stimuli to, and responses from, these three types of cone cells. Cones are mostly concentrated in and near the fovea.
Only a few are present at the sides of the retina. Objects are seen most sharply in focus when their images fall on the fovea, as when one looks at an object directly.
Cone cells and rods are connected through intermediate cells in the retina to nerve fibres of the optic nerve.
When rods and cones are stimulated by light, they connect through adjoining cells within the retina to send an electrical signal to the optic nerve fibres.
The optic nerves send off impulses through these fibres to the brain. The pigment molecules used in the eye are various, but can be used to define the evolutionary distance between different groups, and can also be an aid in determining which are closely related—although problems of convergence do exist.
Opsins are the pigments involved in photoreception. Other pigments, such as melanin, are used to shield the photoreceptor cells from light leaking in from the sides.
The opsin protein group evolved long before the last common ancestor of animals, and has continued to diversify since.
There are two types of opsin involved in vision; c-opsins, which are associated with ciliary-type photoreceptor cells, and r-opsins, associated with rhabdomeric photoreceptor cells.
However, some ganglion cells of vertebrates express r-opsins, suggesting that their ancestors used this pigment in vision, and that remnants survive in the eyes.
They may have been expressed in ciliary cells of larval eyes, which were subsequently resorbed into the brain on metamorphosis to the adult form.
From Wikipedia, the free encyclopedia. This article is about the organ. For the human eye, see Human eye.
For the letter, see I. For other uses, see Eye disambiguation. For other uses, see Eyeball disambiguation , Eyes disambiguation , and Ocular disambiguation.
Organ that detects light and converts it into electro-chemical impulses in neurons. Main article: Compound eye. Further information: Arthropod eye.
Main article: Evolution of the eye. Main article: Colour vision. Annual Review of Neuroscience. Briscoe New York: Oxford University Press.
Belmont: Wadsworth Publishing. Visual Perception: Physiology, Psychology and Ecology. Psychology Press. National Wildlife Magazine.
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Proceedings of the Royal Society of London. B : — The Image Processing Handbook. CRC Press. Send us feedback. Accessed 4 Aug. Keep scrolling for more More Definitions for eye eye.
Entry 1 of 2 : the part of the body that you see with : an ability to understand and appreciate something seen — used to describe the way something looks to you eye.
Entry 1 of 2 1 : the organ of seeing that in vertebrates is a round organ filled with a jellylike material, is located in a bony cavity in the skull, and has a lens which focuses light on the retina 2 : the eye along with its surrounding parts as the eyelids 3 : the colored surface of the iris He has blue eyes.
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Login or Register. Save Word. Log In. That's glass. Illustration of eye Noun eye 1a: 1 optic nerve, 2 blind spot, 3 fovea, 4 sclera, 5 choroid, 6 retina, 7 ciliary body, 8 posterior chamber, 9 anterior chamber, 10 cornea, 11 lens, 12 iris, 13 suspensory ligament, 14 conjunctiva, 15 vitreous humor In the meaning defined above.
More Example Sentences Learn More about eye. Keep scrolling for more. Synonyms for eye Synonyms: Noun band , circle , hoop , loop , ring , round Synonyms: Verb follow , observe , watch Visit the Thesaurus for More.
Did You Know? Recent Examples on the Web: Noun The east coast of Florida is in the forecast path of the storm and some models show the eye coming ashore or brushing the coast, according to the Florida Public Radio Emergency Network.
First Known Use of eye Noun before the 12th century, in the meaning defined at sense 1a Verb 15th century, in the meaning defined at transitive sense 1a 1.
Learn More about eye. Time Traveler for eye The first known use of eye was before the 12th century See more words from the same century.
Watch More on eye. From the Editors at Merriam-Webster. Phrases Related to eye have stars in one's eyes a feast for the eyes a twinkle in one's eye all eyes all eyes are on as far as the eye can see avert one's eyes.
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