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Iris (anatomy)

Index Iris (anatomy)

In humans and most mammals and birds, the iris (plural: irides or irises) is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupil and thus the amount of light reaching the retina. [1]

71 relations: Albinism, Alexander the Great, Alternative medicine, Anastasius I Dicorus, Aniridia, Aperture, Aqueous humour, Australian Shepherd, Blood–ocular barrier, Border Collie, Butterfly, Chromatophore, Ciliary body, Collagen, Coloboma, Color, Conjunctiva, Conjunctivitis, Cornea, Diaphragm (optics), Diffraction, Ectoderm, Encyclopædia Britannica, Epigenetics, Epithelium, Eye, Eye color, Eyespot (mimicry), Glaucoma, Hair, Hemoglobin, Heterochromia iridum, Human eye, Intraocular pressure, Iridoplegia, Iris, Iris dilator muscle, Iris pigment epithelium, Iris recognition, Iris sphincter muscle, Lipofuscin, Long ciliary nerves, Long posterior ciliary arteries, Melanin, Melanosome, Merle (dog coat), Mesoderm, Neural crest, Ocular albinism, Pigment, ..., Polycoria, Pupil, Raman scattering, Rayleigh scattering, Red-eye effect, Retina, Sclera, Short ciliary nerves, Siberian Husky, Skin, Smooth muscle tissue, Sphincter, Striated muscle tissue, Stroma of iris, Tyndall effect, Uvea, Uveitis, Visual system, Waardenburg syndrome, Wave interference, Wing. Expand index (21 more) »


Albinism in humans is a congenital disorder characterized by the complete or partial absence of pigment in the skin, hair and eyes.

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Alexander the Great

Alexander III of Macedon (20/21 July 356 BC – 10/11 June 323 BC), commonly known as Alexander the Great (Aléxandros ho Mégas), was a king (basileus) of the ancient Greek kingdom of Macedon and a member of the Argead dynasty.

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Alternative medicine

Alternative medicine, fringe medicine, pseudomedicine or simply questionable medicine is the use and promotion of practices which are unproven, disproven, impossible to prove, or excessively harmful in relation to their effect — in the attempt to achieve the healing effects of medicine.--> --> --> They differ from experimental medicine in that the latter employs responsible investigation, and accepts results that show it to be ineffective. The scientific consensus is that alternative therapies either do not, or cannot, work. In some cases laws of nature are violated by their basic claims; in some the treatment is so much worse that its use is unethical. Alternative practices, products, and therapies range from only ineffective to having known harmful and toxic effects.--> Alternative therapies may be credited for perceived improvement through placebo effects, decreased use or effect of medical treatment (and therefore either decreased side effects; or nocebo effects towards standard treatment),--> or the natural course of the condition or disease. Alternative treatment is not the same as experimental treatment or traditional medicine, although both can be misused in ways that are alternative. Alternative or complementary medicine is dangerous because it may discourage people from getting the best possible treatment, and may lead to a false understanding of the body and of science.-->---> Alternative medicine is used by a significant number of people, though its popularity is often overstated.--> Large amounts of funding go to testing alternative medicine, with more than US$2.5 billion spent by the United States government alone.--> Almost none show any effect beyond that of false treatment,--> and most studies showing any effect have been statistical flukes. Alternative medicine is a highly profitable industry, with a strong lobby. This fact is often overlooked by media or intentionally kept hidden, with alternative practice being portrayed positively when compared to "big pharma". --> The lobby has successfully pushed for alternative therapies to be subject to far less regulation than conventional medicine.--> Alternative therapies may even be allowed to promote use when there is demonstrably no effect, only a tradition of use. Regulation and licensing of alternative medicine and health care providers varies between and within countries. Despite laws making it illegal to market or promote alternative therapies for use in cancer treatment, many practitioners promote them.--> Alternative medicine is criticized for taking advantage of the weakest members of society.--! Terminology has shifted over time, reflecting the preferred branding of practitioners.. Science Based Medicine--> For example, the United States National Institutes of Health department studying alternative medicine, currently named National Center for Complementary and Integrative Health, was established as the Office of Alternative Medicine and was renamed the National Center for Complementary and Alternative Medicine before obtaining its current name. Therapies are often framed as "natural" or "holistic", in apparent opposition to conventional medicine which is "artificial" and "narrow in scope", statements which are intentionally misleading. --> When used together with functional medical treatment, alternative therapies do not "complement" (improve the effect of, or mitigate the side effects of) treatment.--> Significant drug interactions caused by alternative therapies may instead negatively impact functional treatment, making it less effective, notably in cancer.--> Alternative diagnoses and treatments are not part of medicine, or of science-based curricula in medical schools, nor are they used in any practice based on scientific knowledge or experience.--> Alternative therapies are often based on religious belief, tradition, superstition, belief in supernatural energies, pseudoscience, errors in reasoning, propaganda, fraud, or lies.--> Alternative medicine is based on misleading statements, quackery, pseudoscience, antiscience, fraud, and poor scientific methodology. Promoting alternative medicine has been called dangerous and unethical.--> Testing alternative medicine that has no scientific basis has been called a waste of scarce research resources.--> Critics state that "there is really no such thing as alternative medicine, just medicine that works and medicine that doesn't",--> that the very idea of "alternative" treatments is paradoxical, as any treatment proven to work is by definition "medicine".-->.

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Anastasius I Dicorus

Anastasius I (Flavius Anastasius Augustus; Ἀναστάσιος; 9 July 518) was Byzantine Emperor from 491 to 518.

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Aniridia is the absence of the iris, usually involving both eyes.

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In optics, an aperture is a hole or an opening through which light travels.

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Aqueous humour

The aqueous humour is a transparent, watery fluid similar to plasma, but containing low protein concentrations.

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Australian Shepherd

The Australian Shepherd, often known simply as the "Aussie", is a medium-sized breed of dog that was, despite its name, developed on ranches in the Western United States during the 19th century.

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Blood–ocular barrier

The blood–ocular barrier is a barrier created by endothelium of capillaries of the retina and iris, ciliary epithelium and retinal pigment epithelium.

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Border Collie

The Border Collie is a working and herding dog breed developed in the Anglo-Scottish border region for herding livestock, especially sheep.

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Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which also includes moths.

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Chromatophores are pigment-containing and light-reflecting cells, or groups of cells, found in a wide range of animals including amphibians, fish, reptiles, crustaceans and cephalopods.

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Ciliary body

The ciliary body is a part of the eye that includes the ciliary muscle, which controls the shape of the lens, and the ciliary epithelium, which produces the aqueous humor.

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Collagen is the main structural protein in the extracellular space in the various connective tissues in animal bodies.

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A coloboma (from the Greek koloboma, meaning defect) is a hole in one of the structures of the eye, such as the iris, retina, choroid, or optic disc.

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Color (American English) or colour (Commonwealth English) is the characteristic of human visual perception described through color categories, with names such as red, orange, yellow, green, blue, or purple.

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The conjunctiva lines the inside of the eyelids and covers the sclera (the white of the eye).

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Conjunctivitis, also known as pink eye, is inflammation of the outermost layer of the white part of the eye and the inner surface of the eyelid.

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The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber.

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Diaphragm (optics)

In optics, a diaphragm is a thin opaque structure with an opening (aperture) at its center.

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--> Diffraction refers to various phenomena that occur when a wave encounters an obstacle or a slit.

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Ectoderm is one of the three primary germ layers in the very early embryo.

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Encyclopædia Britannica

The Encyclopædia Britannica (Latin for "British Encyclopaedia"), published by Encyclopædia Britannica, Inc., is a general knowledge English-language encyclopaedia.

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Epigenetics is the study of heritable changes in gene function that do not involve changes in the DNA sequence.

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Epithelium is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue.

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Eyes are organs of the visual system.

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Eye color

Eye color is a polygenic phenotypic character determined by two distinct factors: the pigmentation of the eye's iris and the frequency-dependence of the scattering of light by the turbid medium in the stroma of the iris.

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Eyespot (mimicry)

An eyespot (sometimes ocellus) is an eye-like marking.

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Glaucoma is a group of eye diseases which result in damage to the optic nerve and vision loss.

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Hair is a protein filament that grows from follicles found in the dermis.

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Hemoglobin (American) or haemoglobin (British); abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates (with the exception of the fish family Channichthyidae) as well as the tissues of some invertebrates.

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Heterochromia iridum

Heterochromia is a difference in coloration, usually of the iris but also of hair or skin.

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Human eye

The human eye is an organ which reacts to light and pressure.

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Intraocular pressure

Intraocular pressure (IOP) is the fluid pressure inside the eye.

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Iridoplegia is the paralysis of the sphincter of the iris.

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Iris or IRIS may refer to.

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Iris dilator muscle

The iris dilator muscle (pupil dilator muscle, pupillary dilator, radial muscle of iris, radiating fibers), is a smooth muscle of the eye, running radially in the iris and therefore fit as a dilator.

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Iris pigment epithelium

The iris pigment epithelium (IPE) is a one cell thick layer of cuboidal cells lying behind the iris.

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Iris recognition

Iris recognition is an automated method of biometric identification that uses mathematical pattern-recognition techniques on video images of one or both of the irises of an individual's eyes, whose complex patterns are unique, stable, and can be seen from some distance.

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Iris sphincter muscle

The iris sphincter muscle (pupillary sphincter, pupillary constrictor, circular muscle of iris, circular fibers) is a muscle in the part of the eye called the iris.

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Lipofuscin is the name given to fine yellow-brown pigment granules composed of lipid-containing residues of lysosomal digestion.

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Long ciliary nerves

The long ciliary nerves, two or three in number, are given off from the nasociliary nerve as it crosses the optic nerve.

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Long posterior ciliary arteries

The long posterior ciliary arteries are arteries of the head arising, together with the other ciliary arteries, from the ophthalmic artery.

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Melanin (from μέλας melas, "black, dark") is a broad term for a group of natural pigments found in most organisms.

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A melanosome is an organelle found in animal cells and is the site for synthesis, storage and transport of melanin, the most common light-absorbing pigment found in the animal kingdom.

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Merle (dog coat)

Merle is a pattern in a dog's coat.

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In all bilaterian animals, the mesoderm is one of the three primary germ layers in the very early embryo.

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Neural crest

Neural crest cells are a temporary group of cells unique to chordates of the group Cristozoa that arise from the embryonic ectoderm cell layer, and in turn give rise to a diverse cell lineage—including melanocytes, craniofacial cartilage and bone, smooth muscle, peripheral and enteric neurons and glia.

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Ocular albinism

Ocular albinism is a form of albinism which, in contrast to oculocutaneous albinism, presents primarily in the eyes.

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A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption.

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Polycoria is a pathological condition of the eye characterized by more than one pupillary opening in the iris.

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The pupil is a hole located in the center of the iris of the eye that allows light to strike the retina.

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Raman scattering

Raman scattering or the Raman effect is the inelastic scattering of a photon by molecules which are excited to higher vibrational or rotational energy levels.

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Rayleigh scattering

Rayleigh scattering (pronounced), named after the British physicist Lord Rayleigh (John William Strutt), is the (dominantly) elastic scattering of light or other electromagnetic radiation by particles much smaller than the wavelength of the radiation.

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Red-eye effect

The red-eye effect in photography is the common appearance of red pupils in color photographs of the eyes of humans and several other animals.

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The retina is the innermost, light-sensitive "coat", or layer, of shell tissue of the eye of most vertebrates and some molluscs.

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The sclera, also known as the white of the eye, is the opaque, fibrous, protective, outer layer of the human eye containing mainly collagen and some elastic fiber.

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Short ciliary nerves

The branches of the ciliary ganglion are the short ciliary nerves.

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Siberian Husky

The Siberian Husky (Сибирский хаски) is a Large size working dog breed that originated in Northeast Asia.

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Skin is the soft outer tissue covering vertebrates.

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Smooth muscle tissue

Smooth muscle is an involuntary non-striated muscle.

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A sphincter is a circular muscle that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning.

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Striated muscle tissue

Striated muscle tissue is a muscle tissue that features repeating functional units called sarcomeres, in contrast with smooth muscle tissue which does not.

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Stroma of iris

The stroma of the iris is a fibrovascular layer of tissue.

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Tyndall effect

The Tyndall effect, also known as Willis–Tyndall scattering, is light scattering by particles in a colloids or in a very fine suspension.

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The uvea (/ˈjuːvɪə/) (Lat. uva, grape), also called the uveal layer, uveal coat, uveal tract, vascular tunic or vascular layer is the pigmented middle of the three concentric layers that make up an eye. The name is possibly a reference to its reddish-blue or almost black colour, wrinkled appearance and grape-like size and shape when stripped intact from a cadaveric eye. Its use as a technical term in anatomy and ophthalmology is relatively modern.

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Uveitis is the inflammation of the uvea, the pigmented layer that lies between the inner retina and the outer fibrous layer composed of the sclera and cornea.

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Visual system

The visual system is the part of the central nervous system which gives organisms the ability to process visual detail, as well as enabling the formation of several non-image photo response functions.

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Waardenburg syndrome

Waardenburg syndrome is a rare genetic disorder most often characterized by varying degrees of deafness, minor defects in structures arising from the neural crest, and pigmentation changes.

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Wave interference

In physics, interference is a phenomenon in which two waves superpose to form a resultant wave of greater, lower, or the same amplitude.

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A wing is a type of fin that produces lift, while moving through air or some other fluid.

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Redirects here:

Crypt of Fuchs, Crypts of Fuchs, Irido-, Iris (eye), Iris crypts, Iris diseases, Iris of the eye.


[1] https://en.wikipedia.org/wiki/Iris_(anatomy)

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