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Xanthopsia
Xanthopsia is a color vision deficiency in which there is a dominantly yellow bias in vision due to a yellowing of the optical media of the eye. The most common causes are digoxin's inhibitory action on the sodium pump, and the development of cataracts which can cause a yellow filtering effect. It has been suggested that Van Gogh contracted Xanthopsia as a result of digoxin consumption. Digoxin is a medication derived from digitalis and used to treat various heart conditions. This theory claims Xanthopsia as the cause of the yellow tinting exhibited by many of his works. Xanthopsia is also a rare side-effect of jaundice, in which bilirubin may be deposited into the eye in sufficient quantity to produce a yellow tint to the vision.Weatherall, D. J.; Ledingham, J. G. G.; Warrell, D. A. (1996). ''Oxford Textbook of Medicine''. 3rd ed. Oxford: Oxford University Press. 2055. See also * Cyanopsia References External links Acquired Colour Vision Deficiencies—University of Calgar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digitalis
''Digitalis'' ( or ) is a genus of about 20 species of herbaceous perennial plants, shrubs, and biennials, commonly called foxgloves. ''Digitalis'' is native to Europe, western Asia, and northwestern Africa. The flowers are tubular in shape, produced on a tall spike, and vary in colour with species, from purple to pink, white, and yellow. The scientific name means "finger". The genus was traditionally placed in the figwort family, Scrophulariaceae, but phylogenetic research led taxonomists to move it to the Veronicaceae in 2001. More recent phylogenetic work has placed it in the much enlarged family Plantaginaceae. The best-known species is the common foxglove, '' Digitalis purpurea''. This biennial is often grown as an ornamental plant due to its vivid flowers which range in colour from various purple tints through pink and purely white. The flowers can also possess various marks and spottings. Other garden-worthy species include ''D. ferruginea'', ''D. grandiflora'', '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Vision Deficiency
Color blindness or color vision deficiency (CVD) is the decreased ability to see color or differences in color. It can impair tasks such as selecting ripe fruit, choosing clothing, and reading traffic lights. Color blindness may make some academic activities more difficult. However, issues are generally minor, and the colorblind automatically develop adaptations and coping mechanisms. People with total color blindness (achromatopsia) may also be uncomfortable in bright environments and have decreased visual acuity. The most common cause of color blindness is an inherited problem or variation in the functionality of one or more of the three classes of cone cells in the retina, which mediate color vision. The most common form is caused by a genetic disorder called congenital red–green color blindness. Males are more likely to be color blind than females, because the genes responsible for the most common forms of color blindness are on the X chromosome. Non-color-blind f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanopsia
''Cyanopsia'' is a medical term for seeing everything tinted with blue. It is also referred to as ''blue vision''. Cyanopsia often occurs for a few days, weeks, or months after removal of a cataract from the eye. Cyanopsia also sometimes occurs as a side effect of taking sildenafil, tadalafil, or vardenafil. Cyanopsia is a medical symptom and not a sign. It is a purely subjective state and can be caused by a physical or functional abnormality of the eye, a physical or functional abnormality of the brain, or be purely psychological. Cyanopsia, if unaccompanied by any other sign or symptom, is not an indication of any disease or disorder. Unless it causes an impairment or significant distress, it is not in and of itself diagnostically relevant. Cyanopsia after cataract removal The eye's lens is normally tinted yellow. This reduces the intensity of blue light reaching the retina. When the lens is removed because of cataract, it is usually replaced by an artificial intraocular lens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digoxin
Digoxin (better known as Digitalis), sold under the brand name Lanoxin among others, is a medication used to treat various heart conditions. Most frequently it is used for atrial fibrillation, atrial flutter, and heart failure. Digoxin is one of the oldest medications used in the field of cardiology. It works by increasing myocardial contractility, increasing stroke volume and blood pressure, reducing heart rate, and somewhat extending the time frame of the contraction. Digoxin is taken by mouth or by injection into a vein. Digoxin has a half life of approximately 36 hours given at average doses in patients with normal renal function. It is excreted mostly unchanged in the urine. Common side effects include breast enlargement with other side effects generally due to an excessive dose. These side effects may include loss of appetite, nausea, trouble seeing, confusion, and an irregular heartbeat. Greater care is required in older people and those with poor kidney function. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Pump
Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable isotope is 23Na. The free metal does not occur in nature, and must be prepared from compounds. Sodium is the sixth most abundant element in the Earth's crust and exists in numerous minerals such as feldspars, sodalite, and halite (NaCl). Many salts of sodium are highly water-soluble: sodium ions have been leached by the action of water from the Earth's minerals over eons, and thus sodium and chlorine are the most common dissolved elements by weight in the oceans. Sodium was first isolated by Humphry Davy in 1807 by the electrolysis of sodium hydroxide. Among many other useful sodium compounds, sodium hydroxide (lye) is used in soap manufacture, and sodium chloride (edible salt) is a de-icing agent and a nutrient for animals includin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cataracts
A cataract is a cloudy area in the lens of the eye that leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colors, blurry or double vision, halos around light, trouble with bright lights, and trouble seeing at night. This may result in trouble driving, reading, or recognizing faces. Poor vision caused by cataracts may also result in an increased risk of falling and depression. Cataracts cause 51% of all cases of blindness and 33% of visual impairment worldwide. Cataracts are most commonly due to aging but may also occur due to trauma or radiation exposure, be present from birth, or occur following eye surgery for other problems. Risk factors include diabetes, longstanding use of corticosteroid medication, smoking tobacco, prolonged exposure to sunlight, and alcohol. The underlying mechanism involves accumulation of clumps of protein or yellow-brown pigment in the lens that reduces transmission ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Van Gogh
Vincent Willem van Gogh (; 30 March 185329 July 1890) was a Dutch Post-Impressionist painter who posthumously became one of the most famous and influential figures in Western art history. In a decade, he created about 2,100 artworks, including around 860 oil paintings, most of which date from the last two years of his life. They include landscapes, still lifes, portraits and self-portraits, and are characterised by bold colours and dramatic, impulsive and expressive brushwork that contributed to the foundations of modern art. Not commercially successful, he struggled with severe depression and poverty, eventually leading to his suicide at age thirty-seven. Born into an upper-middle class family, Van Gogh drew as a child and was serious, quiet, and thoughtful. As a young man, he worked as an art dealer, often traveling, but became depressed after he was transferred to London. He turned to religion and spent time as a Protestant missionary in southern Belgium. He drifte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digoxin
Digoxin (better known as Digitalis), sold under the brand name Lanoxin among others, is a medication used to treat various heart conditions. Most frequently it is used for atrial fibrillation, atrial flutter, and heart failure. Digoxin is one of the oldest medications used in the field of cardiology. It works by increasing myocardial contractility, increasing stroke volume and blood pressure, reducing heart rate, and somewhat extending the time frame of the contraction. Digoxin is taken by mouth or by injection into a vein. Digoxin has a half life of approximately 36 hours given at average doses in patients with normal renal function. It is excreted mostly unchanged in the urine. Common side effects include breast enlargement with other side effects generally due to an excessive dose. These side effects may include loss of appetite, nausea, trouble seeing, confusion, and an irregular heartbeat. Greater care is required in older people and those with poor kidney function. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jaundice
Jaundice, also known as icterus, is a yellowish or greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults is typically a sign indicating the presence of underlying diseases involving abnormal heme metabolism, liver dysfunction, or biliary-tract obstruction. The prevalence of jaundice in adults is rare, while jaundice in babies is common, with an estimated 80% affected during their first week of life. The most commonly associated symptoms of jaundice are itchiness, pale feces, and dark urine. Normal levels of bilirubin in blood are below 1.0 mg/ dl (17 μmol/ L), while levels over 2–3 mg/dl (34–51 μmol/L) typically result in jaundice. High blood bilirubin is divided into two types – unconjugated and conjugated bilirubin. Causes of jaundice vary from relatively benign to potentially fatal. High unconjugated bilirubin may be due to excess red blood cell breakdown, large bruises, genetic conditions s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bilirubin
Bilirubin (BR) ( Latin for "red bile") is a red-orange compound that occurs in the normal catabolic pathway that breaks down heme in vertebrates. This catabolism is a necessary process in the body's clearance of waste products that arise from the destruction of aged or abnormal red blood cells. In the first step of bilirubin synthesis, the heme molecule is stripped from the hemoglobin molecule. Heme then passes through various processes of porphyrin catabolism, which varies according to the region of the body in which the breakdown occurs. For example, the molecules excreted in the urine differ from those in the feces. The production of biliverdin from heme is the first major step in the catabolic pathway, after which the enzyme biliverdin reductase performs the second step, producing bilirubin from biliverdin.Boron W, Boulpaep E. Medical Physiology: a cellular and molecular approach, 2005. 984–986. Elsevier Saunders, United States. Ultimately, bilirubin is broken down w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxford Textbook Of Medicine
The ''Oxford Textbook of Medicine'' is an international textbook of medicine. First published in 1983, it is now in its sixth edition. It is primarily aimed at mature physicians looking for information outside their area of particular expertise, but widely used as a reference source by medical students and doctors in training, and by others seeking authoritative accounts of the science and clinical practice of medicine. The ''Oxford Textbook of Medicine'' is available in print and online - where its contents are systematically updated. Description The ''Oxford Textbook of Medicine'' covers the scientific aspects and clinical practice of internal medicine and its subspecialties. It offers practical guidance on clinical management and the prevention of disease. Throughout the book, basic science and clinical practice are integrated, and the implications of research for medical practice are explained. Traditional specialty areas in clinical medicine are covered, and there are sec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Calgary
The University of Calgary (U of C or UCalgary) is a public research university located in Calgary, Alberta, Canada. The University of Calgary started in 1944 as the Calgary branch of the University of Alberta, founded in 1908, prior to being instituted into a separate, autonomous university in 1966. It is composed of 14 faculties and over 85 research institutes and centres. The main campus is located in the northwest quadrant of the city near the Bow River and a smaller south campus is located in the city centre. The main campus houses most of the research facilities and works with provincial and federal research and regulatory agencies, several of which are housed next to the campus such as the Geological Survey of Canada. The main campus covers approximately . A member of the U15, the University of Calgary is also one of Canada's top research universities (based on the number of Canada Research Chairs). The university has a sponsored research revenue of $380.4 million, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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