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Monofixation Syndrome
Monofixation syndrome (MFS) (also: microtropia or microstrabismus) is an eye condition defined by less-than-perfect binocular vision In biology, binocular vision is a type of vision in which an animal has two eyes capable of facing the same direction to perceive a single three-dimensional image of its surroundings. Binocular vision does not typically refer to vision where an .... It is defined by a small angle deviation with suppression of the deviated eye and the presence of binocular peripheral fusion. That is, MFS implies peripheral fusion without central fusion. Aside the manifest small-angle deviation ("tropia"), subjects with MFS often also have a large-angle latent deviation (''phoria''). Their stereoacuity is often in the range of 3000 to 70 arcsecond, and a small central suppression scotoma of 2 to 5 deg. A rare condition, MFS is estimated to affect only 1% of the general population. There are three distinguishable forms of this condition: primary constant, prim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophthalmology
Ophthalmology ( ) is a surgical subspecialty within medicine that deals with the diagnosis and treatment of eye 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. This may include a one-year integrated internship that involves more general medical training in other fields such as internal medicine or general surgery. Following residency, additional specialty training (or fellowship) may be sought in a particular aspect of eye pathology. Ophthalmologists prescribe medications to treat 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 include research as part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binocular Vision
In biology, binocular vision is a type of vision in which an animal has two eyes capable of facing the same direction to perceive a single three-dimensional image of its surroundings. Binocular vision does not typically refer to vision where an animal has eyes on opposite sides of its head and shares no field of view between them, like in some animals. Neurological researcher Manfred Fahle has stated six specific advantages of having two eyes rather than just one: #It gives a creature a "spare eye" in case one is damaged. #It gives a wider field of view. For example, humans have a maximum horizontal field of view of approximately 190 degrees with two eyes, approximately 120 degrees of which makes up the binocular field of view (seen by both eyes) flanked by two uniocular fields (seen by only one eye) of approximately 40 degrees. #It can give stereopsis in which binocular disparity (or parallax) provided by the two eyes' different positions on the head gives precise depth per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereoacuity
Stereoscopic acuity, also stereoacuity, is the smallest detectable depth difference that can be seen in binocular vision. Specification and measurement Stereoacuity is most simply explained by considering one of its earliest test, a two-peg device, named Howard-Dolman test after its inventors: The observer is shown a black peg at a distance of 6m (=20 feet). A second peg, below it, can be moved back and forth until it is just detectably nearer than the fixed one. Stereoacuity is defined as the minimum angle detectable, calculated as the difference between the angles subtended by both positions, A and B. Stereoacuity is possible due to binocular disparity, i.e., the difference in their binocular parallax. Taking into account that a small angle expressed in radians can be approximated by its tangent, the formula to calculate stereoacuity ''dγ'' is this: :d\gamma = c\,a\,dz/(z\,(z - dz)) where ''a'' is the interocular separation of the observer, ''z'' the distance of the fixed pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anomalous Retinal Correspondence
Retinal correspondence is the inherent relationship between paired retinal visual cells in the two eyes. Images from one object stimulate both cells, which transmit the information to the brain, permitting a single visual impression localized in the same direction in space.Cassin, B. and Solomon, S. ''Dictionary of Eye Terminology.'' Gainesville, Florida: Triad Publishing Company, 1990. Types Normal retinal correspondence (NRC) is a binocular condition in which both foveas work together as corresponding retinal points, with resultant images fused in the occipital cortex of the brain. Abnormal retinal correspondence (ARC), also called ''Anomalous retinal correspondence'' is binocular sensory adaptation to compensate for a long-standing eye deviation (i.e. strabismus). The fovea of the straight (non-deviated) eye and non-foveal retinal point of the deviated eye work together, sometimes permitting single binocular vision. See also *Bagolini Striated Glasses Test *Binocular vision ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strabismus Surgery
Strabismus surgery (also: ''extraocular muscle surgery'', ''eye muscle surgery'', or ''eye alignment surgery'') is surgery on the extraocular muscles to correct strabismus, the misalignment of the eyes. Strabismus surgery is a one-day procedure that is usually performed under general anesthesia most commonly by either a neuro- or pediatric ophthalmologist. The patient spends only a few hours in the hospital with minimal preoperative preparation. After surgery, the patient should expect soreness and redness but is generally free to return home. History The earliest successful strabismus surgery intervention is known to have been performed on 26 October 1839 by Johann Friedrich Dieffenbach on a 7-year-old esotropic child; a few earlier attempts had been performed in 1818 by William Gibson of Baltimore, a general surgeon and professor at the University of Maryland. The idea of treating strabismus by cutting some of the extraocular muscle fibers was published in American newspapers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Congenital Esotropia
Infantile esotropia is an ocular condition of early onset in which one or either eye turns inward. It is a specific sub-type of esotropia and has been a subject of much debate amongst ophthalmologists with regard to its naming, diagnostic features, and treatment. Presentation Historically the term 'congenital strabismus' was used to describe constant esotropias with onset between birth and six months of age. However, this term was felt to be an inadequate classification as it covered a variety of esotropias with different causes, features and prognoses. In 1988, American ophthalmologist Gunter K. Von Noorden discussed what he described as 'Essential Infantile Esotropia'. He described the condition as: "early acquired, not... congenital ..., although congenital factors may favor its development between the ages of 3 and 6 months". He identified this squint sub-type as having the following features: # Onset between birth and six months of age. # Large size (greater than 30 diop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marshall Parks
Marshall Miller Parks (July 6, 1918 – July 25, 2005) was an American ophthalmologist known to many as "the father of pediatric ophthalmology".Joe Holley"D.C. Physician Illuminated The Ailments of Young Eyes."''Washington Post''. Sunday, August 21, 2005; Page C11. Early life Parks was born in Old Mission, Michigan to Ruth E. and Reuben Elvin Parks. In 1939, he earned a BS from Illinois College and in 1943 graduated from the Saint Louis University School of Medicine. His success in medical school gained him induction into Alpha Omega Alpha Society. During World War II, Parks served as a medical officer on destroyers in the United States Navy, including the USS ''Gamble'' and USS ''Terror'' during the battle of Iwo Jima. Professional career Parks studied under the guidance of Frank D. Costenbader, the first ophthalmologist to dedicate his practice solely to the care of children.Marshall MM"The History of the Costenbader Society: Costenbader's Challenges."Accessed August 19, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disorders Of Ocular Muscles, Binocular Movement, Accommodation And Refraction
Disorder may refer to randomness, non-order, or no intelligible pattern. Disorder may also refer to: Healthcare * Disorder (medicine), a functional abnormality or disturbance * Mental disorder or psychological disorder, a psychological pattern associated with distress or disability that occurs in an individual and is not a part of normal development or culture: :* Anxiety disorder, different forms of abnormal and pathological fear and anxiety :* Conversion disorder, neurological symptoms such as numbness, blindness, paralysis, or fits, where no neurological explanation is possible :* Obsessive–compulsive disorder, an anxiety disorder characterized by repetitive behaviors aimed at reducing anxiety :* Obsessive–compulsive personality disorder, obsession with perfection, rules, and organization :* Personality disorder, an enduring pattern of inner experience and behavior that deviates markedly from the expectations of the culture of the individual who exhibits it Law enforcement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syndromes
A syndrome is a set of medical signs and symptoms which are correlated with each other and often associated with a particular disease or disorder. The word derives from the Greek σύνδρομον, meaning "concurrence". When a syndrome is paired with a definite cause this becomes a disease. In some instances, a syndrome is so closely linked with a pathogenesis or cause that the words ''syndrome'', ''disease'', and ''disorder'' end up being used interchangeably for them. This substitution of terminology often confuses the reality and meaning of medical diagnoses. This is especially true of inherited syndromes. About one third of all phenotypes that are listed in OMIM are described as dysmorphic, which usually refers to the facial gestalt. For example, Down syndrome, Wolf–Hirschhorn syndrome, and Andersen–Tawil syndrome are disorders with known pathogeneses, so each is more than just a set of signs and symptoms, despite the ''syndrome'' nomenclature. In other instances, a syn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
