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Snow Blindness
Photokeratitis or ultraviolet keratitis is a painful eye condition caused by exposure of insufficiently protected eyes to the ultraviolet (UV) rays from either natural (e.g. intense sunlight) or artificial (e.g. the electric arc during welding) sources. Photokeratitis is akin to a sunburn of the cornea and conjunctiva. The injury may be prevented by wearing eye protection that blocks most of the ultraviolet radiation, such as welding goggles with the proper filters, a welder's helmet, sunglasses rated for sufficient UV protection, or appropriate snow goggles. The condition is usually managed by removal from the source of ultraviolet radiation, covering the corneas, and administration of pain relief. Photokeratitis is known by a number of different terms including: snow blindness, arc eye, welder's flash, bake eyes, corneal flash burns, flash burns, niphablepsia, or keratoconjunctivitis photoelectrica. Signs and symptoms Common symptoms include pain, intense tears, eyelid tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Eye
The human eye is a sensory organ, part of the sensory nervous system, that reacts to visible light and allows humans to use visual information for various purposes including seeing things, keeping balance, and maintaining circadian rhythm. The eye can be considered as a living optical device. It is approximately spherical in shape, with its outer layers, such as the outermost, white part of the eye (the sclera) and one of its inner layers (the pigmented choroid) keeping the eye essentially light tight except on the eye's optic axis. In order, along the optic axis, the optical components consist of a first lens (the cornea—the clear part of the eye) that accomplishes most of the focussing of light from the outside world; then an aperture (the pupil) in a diaphragm (the iris—the coloured part of the eye) that controls the amount of light entering the interior of the eye; then another lens (the crystalline lens) that accomplishes the remaining focussing of light into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polar Regions
The polar regions, also called the frigid zones or polar zones, of Earth are the regions of the planet that surround its geographical poles (the North and South Poles), lying within the polar circles. These high latitudes are dominated by floating sea ice covering much of the Arctic Ocean in the north, and by the Antarctic ice sheet on the continent of Antarctica and the Southern Ocean in the south. Definitions The Arctic has various definitions, including the region north of the Arctic Circle (currently Epoch 2010 at 66°33'44" N), or just the region north of 60° north latitude, or the region from the North Pole north to the timberline. The Antarctic is usually defined simply as south of 60° south latitude, or the continent of Antarctica. The 1959 Antarctic Treaty uses the former definition. The two polar regions are distinguished from the other two climatic and biometric belts of Earth, a tropics belt near the equator, and two middle latitude regions located between th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinew
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability to withstand significant amounts of tension. Tendons are similar to ligaments; both are made of collagen. Ligaments connect one bone to another, while tendons connect muscle to bone. Structure Histologically, tendons consist of dense regular connective tissue. The main cellular component of tendons are specialized fibroblasts called tendon cells (tenocytes). Tenocytes synthesize the extracellular matrix of tendons, abundant in densely packed collagen fibers. The collagen fibers are parallel to each other and organized into tendon fascicles. Individual fascicles are bound by the endotendineum, which is a delicate loose connective tissue containing thin collagen fibrils and elastic fibres. Groups of fascicles are bounded by the epitenon, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antler
Antlers are extensions of an animal's skull found in members of the Cervidae (deer) family. Antlers are a single structure composed of bone, cartilage, fibrous tissue, skin, nerves, and blood vessels. They are generally found only on males, with the exception of reindeer/caribou. Antlers are shed and regrown each year and function primarily as objects of sexual attraction and as weapons. In contrast to antlers, horns—found on pronghorns and bovids, such as sheep, goats, bison and cattle—are two-part structures that usually do not shed. A horn's interior of bone is covered by an exterior sheath made of keratin (the same material as human fingernails and toenails). Etymology Antler comes from the Old French ''antoillier '' (see present French : "Andouiller", from'' ant-, ''meaning before,'' oeil, ''meaning eye and'' -ier'', a suffix indicating an action or state of being) possibly from some form of an unattested Latin word ''*anteocularis'', "before the eye" (and appl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caribou
Reindeer (in North American English, known as caribou if wild and ''reindeer'' if domesticated) are deer in the genus ''Rangifer''. For the last few decades, reindeer were assigned to one species, ''Rangifer tarandus'', with about 10 subspecies. A 2022 revision of the genus elevated five of the subspecies to species (see Taxonomy below). They have a circumpolar distribution and are native to the Arctic, sub-Arctic, tundra, boreal forest, and mountainous regions of northern Europe, Siberia, and North America. Reindeer occur in both migratory and sedentary populations, and their herd sizes vary greatly in different regions. The tundra subspecies are adapted for extreme cold, and some are adapted for long-distance migration. Reindeer vary greatly in size and color from the smallest species, the Svalbard reindeer (''R. t. platyrhynchus''), to the largest subspecies, Osborn's caribou (''R. t. osborni''). Although reindeer are quite numerous, some species and subspecies are in d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Driftwood
__NOTOC__ Driftwood is wood that has been washed onto a shore or beach of a sea, lake, or river by the action of winds, tides or waves. In some waterfront areas, driftwood is a major nuisance. However, the driftwood provides shelter and food for birds, fish and other aquatic species as it floats in the ocean. Gribbles, shipworms and bacteria decompose the wood and gradually turn it into nutrients that are reintroduced to the food web A food web is the natural interconnection of food chains and a graphical representation of what-eats-what in an ecological community. Another name for food web is consumer-resource system. Ecologists can broadly lump all life forms into one o .... Sometimes, the partially decomposed wood washes ashore, where it also shelters birds, plants, and other species. Driftwood can become the foundation for sand dunes. Most driftwood is the remains of trees, in whole or part, that have been washed into the ocean, due to flooding, high winds, or ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snow Goggles
Snow goggles (Inuktitut: or , syllabics: or ; esu, nigaugek, ) are a type of eyewear traditionally used by the Inuit and the Yupik peoples of the Arctic to prevent snow blindness. The goggles fit tightly against the face so that the only light entering is through the slits, and soot is sometimes applied to the inside to help cut down on glare. The slits are made narrow not only to reduce the amount of light entering but also to improve the visual acuity. Wider slits result in a larger field of view. Terminology Like other Inuit language words, such as inukhuk/inuksuk, a different word may be used in different dialects. In the Kivalliq dialect, () is used, while the North Baffin dialect uses (). Both words are also used to refer to sunglasses. In Central Yup'ik, snow goggles are called , while in Cup'ig they are ''igguag''. In Siberian Yupik, the word is . See also * Pinhole glasses References {{DEFAULTSORT:Inuit Snow Goggles Goggles Snow goggles Snow goggles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Peoples
Circumpolar peoples and Arctic peoples are umbrella terms for the various Indigenous peoples of the Arctic. Prehistory The earliest inhabitants of North America's central and eastern Arctic are referred to as the Arctic small tool tradition (AST) and existed c. 2500 BC. AST consisted of several Paleo-Eskimo cultures, including the Independence cultures and Pre-Dorset culture.Gibbon, pp. 28–31 The Dorset culture (Inuktitut: ''Tuniit'' or ''Tunit'') refers to the next inhabitants of central and eastern Arctic. The Dorset culture evolved because of technological and economic changes during the period of 1050–550 BC. With the exception of the Quebec/Labrador peninsula, the Dorset culture vanished around 1500 AD. Dorset/Thule culture transition dates around the 9th–10th centuries. Scientists theorize that there may have been cross-contact of the two cultures with sharing of technology, such as fashioning harpoon heads, or the Thule may have found Dorset remnants and adapted thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yupik Peoples
The Yupik (plural: Yupiit) (; russian: Юпикские народы) are a group of indigenous or aboriginal peoples of western, southwestern, and southcentral Alaska and the Russian Far East. They are related to the Inuit and Iñupiat. Yupik peoples include the following: * Alutiiq, or Sugpiaq, of the Alaska Peninsula and coastal and island areas of southcentral Alaska. * Yup'ik or Central Alaskan Yup'ik of the Yukon–Kuskokwim Delta, the Kuskokwim River, and along the northern coast of Bristol Bay as far east as Nushagak Bay and the northern Alaska Peninsula at Naknek River and Egegik Bay in Alaska. * Siberian Yupik, including Naukan, Chaplino,Achirgina-Arsiak, Tatiana"Northeastern Siberian: Yupik (Asiatic Eskimo)."''Alaska Native Collections.'' 1996. Retrieved 20 July 2012. and — in a linguistic capacity — the Sirenik of the Russian Far East and St. Lawrence Island in western Alaska. Population The Yup'ik are by far the most numerous of the various Alaska Native gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inuit
Inuit (; iu, ᐃᓄᐃᑦ 'the people', singular: Inuk, , dual: Inuuk, ) are a group of culturally similar indigenous peoples inhabiting the Arctic and subarctic regions of Greenland, Labrador, Quebec, Nunavut, the Northwest Territories, and Alaska. Inuit languages are part of the Eskimo–Aleut languages, also known as Inuit-Yupik-Unangan, and also as Eskaleut. Inuit Sign Language is a critically endangered language isolate used in Nunavut. Inuit live throughout most of Northern Canada in the territory of Nunavut, Nunavik in the northern third of Quebec, Nunatsiavut and NunatuKavut in Labrador, and in various parts of the Northwest Territories, particularly around the Arctic Ocean, in the Inuvialuit Settlement Region. With the exception of NunatuKavut, these areas are known, primarily by Inuit Tapiriit Kanatami, as Inuit Nunangat. In Canada, sections 25 and 35 of the Constitution Act of 1982 classify Inuit as a distinctive group of Aboriginal Canadians wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunglasses
Sunglasses or sun glasses (informally called shades or sunnies; more names below) are a form of protective eyewear designed primarily to prevent bright sunlight and high-energy visible light from damaging or discomforting the eyes. They can sometimes also function as a visual aid, as variously termed spectacles or glasses exist, featuring lenses that are colored, polarized or darkened. In the early 20th century, they were also known as sun cheaters (cheaters then being an American slang term for glasses). Since the 1930s, sunglasses have been a popular fashion accessory, especially on the beach. The American Optometric Association recommends wearing sunglasses that block ultraviolet radiation (UV) whenever a person is in the sunlight to protect the eyes from UV and blue light, which can cause several serious eye problems. Their usage is mandatory immediately after some surgical procedures, such as LASIK, and recommended for a certain time period in dusty areas, when leaving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inuit Snow Goggles
Snow goggles (Inuktitut: or , syllabics: or ; esu, nigaugek, ) are a type of eyewear traditionally used by the Inuit and the Yupik peoples of the Arctic to prevent snow blindness. The goggles fit tightly against the face so that the only light entering is through the slits, and soot is sometimes applied to the inside to help cut down on glare. The slits are made narrow not only to reduce the amount of light entering but also to improve the visual acuity. Wider slits result in a larger field of view. Terminology Like other Inuit language words, such as inukhuk/inuksuk, a different word may be used in different dialects. In the Kivalliq dialect, () is used, while the North Baffin dialect uses (). Both words are also used to refer to sunglasses. In Central Yup'ik, snow goggles are called , while in Cup'ig they are ''igguag''. In Siberian Yupik, the word is . See also * Pinhole glasses References {{DEFAULTSORT:Inuit Snow Goggles Goggles Snow goggles Snow goggles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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