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Astigmatism (film)
Astigmatism is a type of refractive error due to rotational asymmetry in the eye's refractive power. The lens and cornea of an eye without astigmatism are nearly spherical, with only a single radius of curvature, and any refractive errors present can be corrected with simple glasses. In an eye with astigmatism, either the lens or the cornea is slightly egg-shaped, with higher curvature in one direction than the other. This gives distorted or blurred vision at any distance and requires corrective lenses that apply different optical powers at different rotational angles. Astigmatism can lead to symptoms that include eyestrain, headaches, and trouble driving at night. Astigmatism often is present at birth, but can change or develop later in life. If it occurs in early life and is left untreated, it may result in amblyopia. The cause of astigmatism is unclear, although it is believed to be partly related to genetic factors. The underlying mechanism involves an irregular curv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophthalmology
Ophthalmology (, ) is the branch of medicine that deals with the diagnosis, treatment, and surgery of eye diseases and disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a medical degree, a doctor specialising in ophthalmology must pursue additional postgraduate residency training specific to that field. In the United States, following graduation from medical school, one must complete a four-year residency in ophthalmology to become an ophthalmologist. Following residency, additional specialty training (or fellowship) may be sought in a particular aspect of eye pathology. Ophthalmologists prescribe medications to treat ailments, such as eye diseases, implement laser therapy, and perform surgery when needed. Ophthalmologists provide both primary and specialty eye care—medical and surgical. Most ophthalmologists participate in academic research on eye diseases at some point in their training and many inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eye Examination
An eye examination, commonly known as an eye test, is a series of tests performed to assess Visual acuity, vision and ability to Focus (optics), focus on and discern objects. It also includes other tests and examinations of the human eye, eyes. Eye examinations are primarily performed by an optometrist, ophthalmologist, or an orthoptist. Health care professionals often recommend that all people should have periodic and thorough eye examinations as part of routine primary care, especially since many eye diseases are asymptomatic. Typically, a healthy individual who otherwise has no concerns with their eyes receives an eye exam once in their 20s and twice in their 30s. Eye examinations may detect potentially treatable blindness, blinding eye diseases, ocular manifestation of systemic disease, ocular manifestations of systemic disease, or signs of tumour, tumors or other anomalies of the Human brain, brain. A full eye examination consists of a comprehensive evaluation of medical h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ACP2
Lysosomal acid phosphatase is an enzyme that in humans is encoded by the ''ACP2'' gene. Lysosomal acid phosphatase is composed of two subunits, alpha and beta, and is chemically and genetically distinct from red cell acid phosphatase. Lysosomal acid phosphatase 2 is a member of a family of distinct isoenzymes which hydrolyze orthophosphoric monoesters to alcohol and phosphate. Acid phosphatase deficiency is caused by mutation In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, ...s in the ACP2 (beta subunit) and ACP3 (alpha subunit) genes. References Further reading * * * * * * * * * * * * * * * * * * External links * Human proteins {{gene-11-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CLDN7
Claudin-7 is a protein that in humans is encoded by the ''CLDN7'' gene. It belongs to the group of claudin Claudins are a family of proteins which, along with occludin, are the most important components of the tight junctions ( zonulae occludentes). Tight junctions establish the paracellular barrier that controls the flow of molecules in the inter ...s. Claudins, such as CLDN7, are involved in the formation of tight junctions between epithelial cells. Tight junctions restrict lateral diffusion of lipids and membrane proteins, and thereby physically define the border between the apical and basolateral compartments of epithelial cells (Zheng et al., 2003). upplied by OMIMref name="entrez" /> References External links * Further reading * * * * * * * * * * * * * * * {{gene-17-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FIP1L1
Factor interacting with PAPOLA and CPSF1 (i.e, FIP1L1; also termed Pre-mRNA 3'-end-processing factor FIP1) is a protein that in humans is encoded by the ''FIP1L1'' gene (also known as Rhe, FIP1, and hFip1). A medically important aspect of the ''FIP1L1'' gene is its fusion with other genes to form fusion genes which cause clonal hypereosinophilia and leukemic diseases in humans. Gene The human ''FIP1L1'' gene is located on chromosome 4 at position q12 (4q12), contains 19 exons, and codes for a complete protein consisting of 594 amino acids. However, alternative splicing of its precursor mRNA results in multiple transcript variants encoding distinct FIP1L1 protein isoforms. The ''FIP1L1'' gene is found in a wide range of species, being designated as FIP1 in ''Saccharomyces cerevisiae'' (yeast) and fip1l1 in coho salmon as well as mice and numerous other mammalian species. In humans, an interstitial chromosomal deletion of about 800 kilobases at 4q12 deletes the ''CHIC2'' gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PDGFRA
Platelet-derived growth factor receptor A, also termed CD140a, is a Receptor (biochemistry), receptor located on the surface of a wide range of cell types. The protein is encoded in the human by the ''PDGFRA'' gene. This receptor binds to certain isoforms of platelet-derived growth factors (PDGFs) and thereby becomes active in stimulating cell signaling pathways that elicit responses such as Cell growth, cellular growth and cellular differentiation, differentiation. The receptor is critical for the embryonic development of certain tissues and organs, and for their maintenance, particularly hematologic tissues, throughout life. Mutations in ''PDGFRA'', are associated with an array of clinically significant neoplasms, notably ones of the clonal hypereosinophilia class of malignancies, as well as gastrointestinal stromal tumors (GISTs). Overall structure This gene encodes a typical receptor tyrosine kinase, which is a transmembrane protein consisting of an extracellular ligand bind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genome-wide Association Study
In genomics, a genome-wide association study (GWA study, or GWAS), is an observational study of a genome-wide set of Single-nucleotide polymorphism, genetic variants in different individuals to see if any variant is associated with a trait. GWA studies typically focus on associations between single-nucleotide polymorphisms (SNPs) and traits like major human diseases, but can equally be applied to any other genetic variants and any other organisms. When applied to human data, GWA studies compare the DNA of participants having varying phenotypes for a particular trait or disease. These participants may be people with a disease (cases) and similar people without the disease (controls), or they may be people with different phenotypes for a particular trait, for example blood pressure. This approach is known as phenotype-first, in which the participants are classified first by their clinical manifestation(s), as opposed to Genotype-first approach, genotype-first. Each person gives a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Migraine
Migraine (, ) is a complex neurological disorder characterized by episodes of moderate-to-severe headache, most often unilateral and generally associated with nausea, and light and sound sensitivity. Other characterizing symptoms may include vomiting, cognitive dysfunction, allodynia, and dizziness. Exacerbation or worsening of headache symptoms during physical activity is another distinguishing feature. Up to one-third of people with migraine experience aura, a premonitory period of sensory disturbance widely accepted to be caused by cortical spreading depression at the onset of a migraine attack. Although primarily considered to be a headache disorder, migraine is highly heterogenous in its clinical presentation and is better thought of as a spectrum disease rather than a distinct clinical entity. Disease burden can range from episodic discrete attacks to chronic disease. Migraine is believed to be caused by a mixture of environmental and genetic factors that influe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asthenopia
Eye strain, also medically termed as asthenopia (), is a common eye condition characterized by non-specific symptoms such as fatigue, pain in or around the eyes, blurred vision, headache, and occasional double vision. These symptoms tend to arise after long-term use of computers, staring at phone screens, digital devices, reading, or other activities that involve extended visual tasks. Various causes contribute to eye strain, including uncorrected vision problems, digital device usage, environmental factors, and underlying health conditions. When concentrating on a visually intense task, such as continuously focusing on a book or computer monitor, the ciliary muscles and the extraocular muscles are strained, also contributing to the symptoms. These symptoms are broadly classified into external (related to the ocular surface) and internal symptom factors (related to eye muscles). Treatment involves environmental modifications, visual aids, and taking periodic breaks. The e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squinting
Squinting is the action of looking at something with partially closed eyes. Squinting is most often practiced by people who suffer from refractive errors of the eye who either do not have or are not using their glasses. Squinting helps momentarily improve their eyesight by slightly changing the shape of the eye to make it rounder, which helps light properly reach the fovea. Squinting also decreases the amount of light entering the eye, making it easier to focus on what the observer is looking at by removing rays of light which enter the eye at an angle and would need to otherwise be focused by the observer's faulty lens and cornea. Pinhole glasses, which severely restrict the amount of light entering the cornea, have the same effect as squinting. It is a common belief that squinting worsens eyesight. However, according to Robert MacLaren, a professor of ophthalmology at the University of Oxford, this is nothing more than an old wives' tale: the only damage that can be caused ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Vision
Diplopia is the simultaneous perception of two images of a single object that may be displaced in relation to each other. Also called double vision, it is a loss of visual focus under regular conditions, and is often voluntary. However, when occurring involuntarily, it results from impaired function of the extraocular muscles, where both eyes are still functional, but they cannot turn to target the desired object. Problems with these muscles may be due to mechanical problems, disorders of the neuromuscular junction, disorders of the cranial nerves ( III, IV, and VI) that innervate the muscles, and occasionally disorders involving the supranuclear oculomotor pathways or ingestion of toxins. Diplopia can be one of the first signs of a systemic disease, particularly to a muscular or neurological process, and it may disrupt a person's balance, movement, or reading abilities. Causes Diplopia has a diverse range of ophthalmologic, infectious, autoimmune, neurological, and neoplastic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Young (scientist)
Thomas Young Fellow of the Royal Society, FRS (13 June 177310 May 1829) was a British polymath who made notable contributions to the fields of Visual perception, vision, light, solid mechanics, energy, physiology, language, harmony, musical harmony, and Egyptology. He was instrumental in the decipherment of Egyptian hieroglyphs, specifically the Rosetta Stone. Young has been described as "The Last Man Who Knew Everything". His work influenced that of William Herschel, Hermann von Helmholtz, James Clerk Maxwell, and Albert Einstein. Young is credited with establishing Christiaan Huygens' wave theory of light, in contrast to the corpuscular theory of Isaac Newton. Young's work was subsequently supported by the work of Augustin-Jean Fresnel. Personal life Young belonged to a Quaker family of Milverton, Somerset, where he was born in 1773, the eldest of ten children. By the age of fourteen, Young had learned Greek language, Greek, Latin, French language, French, Italian language, It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
