The turning inward of the lines of sight toward each other.
Disorders that feature impairment of eye movements as a primary manifestation of disease. These conditions may be divided into infranuclear, nuclear, and supranuclear disorders. Diseases of the eye muscles or oculomotor cranial nerves (III, IV, and VI) are considered infranuclear. Nuclear disorders are caused by disease of the oculomotor, trochlear, or abducens nuclei in the BRAIN STEM. Supranuclear disorders are produced by dysfunction of higher order sensory and motor systems that control eye movements, including neural networks in the CEREBRAL CORTEX; BASAL GANGLIA; CEREBELLUM; and BRAIN STEM. Ocular torticollis refers to a head tilt that is caused by an ocular misalignment. Opsoclonus refers to rapid, conjugate oscillations of the eyes in multiple directions, which may occur as a parainfectious or paraneoplastic condition (e.g., OPSOCLONUS-MYOCLONUS SYNDROME). (Adams et al., Principles of Neurology, 6th ed, p240)
A condition in which the intraocular pressure is elevated above normal and which may lead to glaucoma.
The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.
The study and treatment of defects in binocular vision resulting from defects in the optic musculature or of faulty visual habits. It involves a technique of eye exercises designed to correct the visual axes of eyes not properly coordinated for binocular vision.
Infection caused by the protozoan parasite TOXOPLASMA in which there is extensive connective tissue proliferation, the retina surrounding the lesions remains normal, and the ocular media remain clear. Chorioretinitis may be associated with all forms of toxoplasmosis, but is usually a late sequel of congenital toxoplasmosis. The severe ocular lesions in infants may lead to blindness.
The dioptric adjustment of the EYE (to attain maximal sharpness of retinal imagery for an object of regard) referring to the ability, to the mechanism, or to the process. Ocular accommodation is the effecting of refractive changes by changes in the shape of the CRYSTALLINE LENS. Loosely, it refers to ocular adjustments for VISION, OCULAR at various distances. (Cline et al., Dictionary of Visual Science, 4th ed)
The blending of separate images seen by each eye into one composite image.
Albinism affecting the eye in which pigment of the hair and skin is normal or only slightly diluted. The classic type is X-linked (Nettleship-Falls), but an autosomal recessive form also exists. Ocular abnormalities may include reduced pigmentation of the iris, nystagmus, photophobia, strabismus, and decreased visual acuity.
The functional superiority and preferential use of one eye over the other. The term is usually applied to superiority in sighting (VISUAL PERCEPTION) or motor task but not difference in VISUAL ACUITY or dysfunction of one of the eyes. Ocular dominance can be modified by visual input and NEUROTROPHIC FACTORS.
Refraction of LIGHT effected by the media of the EYE.
Measurement of ocular tension (INTRAOCULAR PRESSURE) with a tonometer. (Cline, et al., Dictionary of Visual Science, 4th ed)
Processes and properties of the EYE as a whole or of any of its parts.
Tumors or cancer of the EYE.
The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)
Damage or trauma inflicted to the eye by external means. The concept includes both surface injuries and intraocular injuries.
Misalignment of the visual axes of the eyes. In comitant strabismus the degree of ocular misalignment does not vary with the direction of gaze. In noncomitant strabismus the degree of misalignment varies depending on direction of gaze or which eye is fixating on the target. (Miller, Walsh & Hoyt's Clinical Neuro-Ophthalmology, 4th ed, p641)
The pressure of the fluids in the eye.
Tuberculous infection of the eye, primarily the iris, ciliary body, and choroid.
The fluid secreted by the lacrimal glands. This fluid moistens the CONJUNCTIVA and CORNEA.
Voluntary or reflex-controlled movements of the eye.
The muscles that move the eye. Included in this group are the medial rectus, lateral rectus, superior rectus, inferior rectus, inferior oblique, superior oblique, musculus orbitalis, and levator palpebrae superioris.
Sterile solutions that are intended for instillation into the eye. It does not include solutions for cleaning eyeglasses or CONTACT LENS SOLUTIONS.
The positioning and accommodation of eyes that allows the image to be brought into place on the FOVEA CENTRALIS of each eye.
Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.
Mild to severe infections of the eye and its adjacent structures (adnexa) by adult or larval protozoan or metazoan parasites.
A form of ocular misalignment where the visual axes diverge inappropriately. For example, medial rectus muscle weakness may produce this condition as the affected eye will deviate laterally upon attempted forward gaze. An exotropia occurs due to the relatively unopposed force exerted on the eye by the lateral rectus muscle, which pulls the eye in an outward direction.
Infection, moderate to severe, caused by bacteria, fungi, or viruses, which occurs either on the external surface of the eye or intraocularly with probable inflammation, visual impairment, or blindness.
A process of complicated morphogenetic cell movements that reorganizes a bilayer embryo into one with three GERM LAYERS and specific orientation (dorsal/ventral; anterior/posterior). Gastrulation describes the germ layer development of a non-mammalian BLASTULA or that of a mammalian BLASTOCYST.
Inflammation of part or all of the uvea, the middle (vascular) tunic of the eye, and commonly involving the other tunics (sclera and cornea, and the retina). (Dorland, 27th ed)
Corneal and conjunctival dryness due to deficient tear production, predominantly in menopausal and post-menopausal women. Filamentary keratitis or erosion of the conjunctival and corneal epithelium may be caused by these disorders. Sensation of the presence of a foreign body in the eye and burning of the eyes may occur.
The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain.
Abnormally low intraocular pressure often related to chronic inflammation (uveitis).
A form of ocular misalignment characterized by an excessive convergence of the visual axes, resulting in a "cross-eye" appearance. An example of this condition occurs when paralysis of the lateral rectus muscle causes an abnormal inward deviation of one eye on attempted gaze.
Deviations from the average or standard indices of refraction of the eye through its dioptric or refractive apparatus.
The transparent, semigelatinous substance that fills the cavity behind the CRYSTALLINE LENS of the EYE and in front of the RETINA. It is contained in a thin hyaloid membrane and forms about four fifths of the optic globe.
Diseases of the cornea.
The clear, watery fluid which fills the anterior and posterior chambers of the eye. It has a refractive index lower than the crystalline lens, which it surrounds, and is involved in the metabolism of the cornea and the crystalline lens. (Cline et al., Dictionary of Visual Science, 4th ed, p319)
The most anterior portion of the uveal layer, separating the anterior chamber from the posterior. It consists of two layers - the stroma and the pigmented epithelium. Color of the iris depends on the amount of melanin in the stroma on reflection from the pigmented epithelium.
Congenital absence of or defects in structures of the eye; may also be hereditary.
The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.
A ring of tissue extending from the scleral spur to the ora serrata of the RETINA. It consists of the uveal portion and the epithelial portion. The ciliary muscle is in the uveal portion and the ciliary processes are in the epithelial portion.
The front third of the eyeball that includes the structures between the front surface of the cornea and the front of the VITREOUS BODY.
An ocular disease, occurring in many forms, having as its primary characteristics an unstable or a sustained increase in the intraocular pressure which the eye cannot withstand without damage to its structure or impairment of its function. The consequences of the increased pressure may be manifested in a variety of symptoms, depending upon type and severity, such as excavation of the optic disk, hardness of the eyeball, corneal anesthesia, reduced visual acuity, seeing of colored halos around lights, disturbed dark adaptation, visual field defects, and headaches. (Dictionary of Visual Science, 4th ed)
The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)
A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.
The thin, highly vascular membrane covering most of the posterior of the eye between the RETINA and SCLERA.
A pair of ophthalmic lenses in a frame or mounting which is supported by the nose and ears. The purpose is to aid or improve vision. It does not include goggles or nonprescription sun glasses for which EYE PROTECTIVE DEVICES is available.
The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. It receives the tendons of insertion of the extraocular muscles and at the corneoscleral junction contains the canal of Schlemm. (From Cline et al., Dictionary of Visual Science, 4th ed)
Application of pharmaceutically active agents on the tissues of the EYE.
The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. (Cline et al., Dictionary of Visual Science, 4th ed, p109)
The relationships of groups of organisms as reflected by their genetic makeup.
Infections in the inner or external eye caused by microorganisms belonging to several families of bacteria. Some of the more common genera found are Haemophilus, Neisseria, Staphylococcus, Streptococcus, and Chlamydia.
Filarial infection of the eyes transmitted from person to person by bites of Onchocerca volvulus-infected black flies. The microfilariae of Onchocerca are thus deposited beneath the skin. They migrate through various tissues including the eye. Those persons infected have impaired vision and up to 20% are blind. The incidence of eye lesions has been reported to be as high as 30% in Central America and parts of Africa.
A chronic blistering disease with predilection for mucous membranes and less frequently the skin, and with a tendency to scarring. It is sometimes called ocular pemphigoid because of conjunctival mucous membrane involvement.
Involuntary movements of the eye that are divided into two types, jerk and pendular. Jerk nystagmus has a slow phase in one direction followed by a corrective fast phase in the opposite direction, and is usually caused by central or peripheral vestibular dysfunction. Pendular nystagmus features oscillations that are of equal velocity in both directions and this condition is often associated with visual loss early in life. (Adams et al., Principles of Neurology, 6th ed, p272)
Images seen by one eye.
Stratified squamous epithelium that covers the outer surface of the CORNEA. It is smooth and contains many free nerve endings.
A transparent, biconvex structure of the EYE, enclosed in a capsule and situated behind the IRIS and in front of the vitreous humor (VITREOUS BODY). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the CILIARY BODY is crucial for OCULAR ACCOMMODATION.
The difference between two images on the retina when looking at a visual stimulus. This occurs since the two retinas do not have the same view of the stimulus because of the location of our eyes. Thus the left eye does not get exactly the same view as the right eye.
Each of the upper and lower folds of SKIN which cover the EYE when closed.
The aperture in the iris through which light passes.
Inflammation of the choroid in which the sensory retina becomes edematous and opaque. The inflammatory cells and exudate may burst through the sensory retina to cloud the vitreous body.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
The act of knowing or the recognition of a distance by recollective thought, or by means of a sensory process which is under the influence of set and of prior experience.
The developmental stage that follows BLASTULA or BLASTOCYST. It is characterized by the morphogenetic cell movements including invagination, ingression, and involution. Gastrulation begins with the formation of the PRIMITIVE STREAK, and ends with the formation of three GERM LAYERS, the body plan of the mature organism.
The application of drug preparations to the surfaces of the body, especially the skin (ADMINISTRATION, CUTANEOUS) or mucous membranes. This method of treatment is used to avoid systemic side effects when high doses are required at a localized area or as an alternative systemic administration route, to avoid hepatic processing for example.
Inflammation of the cornea.
Neural tracts connecting one part of the nervous system with another.
The selected form given to a natural tooth when it is reduced by instrumentation to receive a prosthesis (e.g., artificial crown or a retainer for a fixed or removable prosthesis). The selection of the form is guided by clinical circumstances and physical properties of the materials that make up the prosthesis. (Boucher's Clinical Dental Terminology, 4th ed, p239)
Term generally used to describe complaints related to refractive error, ocular muscle imbalance, including pain or aching around the eyes, burning and itchiness of the eyelids, ocular fatigue, and headaches.
Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.
Paralysis of one or more of the ocular muscles due to disorders of the eye muscles, neuromuscular junction, supporting soft tissue, tendons, or innervation to the muscles.
Visual impairments limiting one or more of the basic functions of the eye: visual acuity, dark adaptation, color vision, or peripheral vision. These may result from EYE DISEASES; OPTIC NERVE DISEASES; VISUAL PATHWAY diseases; OCCIPITAL LOBE diseases; OCULAR MOTILITY DISORDERS; and other conditions (From Newell, Ophthalmology: Principles and Concepts, 7th ed, p132).
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
Glaucoma in which the angle of the anterior chamber is open and the trabecular meshwork does not encroach on the base of the iris.
An abrupt voluntary shift in ocular fixation from one point to another, as occurs in reading.
Infections of the eye caused by minute intracellular agents. These infections may lead to severe inflammation in various parts of the eye - conjunctiva, iris, eyelids, etc. Several viruses have been identified as the causative agents. Among these are Herpesvirus, Adenovirus, Poxvirus, and Myxovirus.
Computer-based representation of physical systems and phenomena such as chemical processes.
Inflammation of the eyelids.
A gelatinous membrane overlying the acoustic maculae of SACCULE AND UTRICLE. It contains minute crystalline particles (otoliths) of CALCIUM CARBONATE and protein on its outer surface. In response to head movement, the otoliths shift causing distortion of the vestibular hair cells which transduce nerve signals to the BRAIN for interpretation of equilibrium.
Bony cavity that holds the eyeball and its associated tissues and appendages.
Elements of limited time intervals, contributing to particular results or situations.
An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.
An abnormal twisting or rotation of a bodily part or member on its axis.
Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.
A refractive error in which rays of light entering the EYE parallel to the optic axis are brought to a focus in front of the RETINA when accommodation (ACCOMMODATION, OCULAR) is relaxed. This results from an overly curved CORNEA or from the eyeball being too long from front to back. It is also called nearsightedness.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Refers to any inflammation of the sclera including episcleritis, a benign condition affecting only the episclera, which is generally short-lived and easily treated. Classic scleritis, on the other hand, affects deeper tissue and is characterized by higher rates of visual acuity loss and even mortality, particularly in necrotizing form. Its characteristic symptom is severe and general head pain. Scleritis has also been associated with systemic collagen disease. Etiology is unknown but is thought to involve a local immune response. Treatment is difficult and includes administration of anti-inflammatory and immunosuppressive agents such as corticosteroids. Inflammation of the sclera may also be secondary to inflammation of adjacent tissues, such as the conjunctiva.
A series of tests used to assess various functions of the eyes.
A beta-adrenergic antagonist similar in action to PROPRANOLOL. The levo-isomer is the more active. Timolol has been proposed as an antihypertensive, antiarrhythmic, antiangina, and antiglaucoma agent. It is also used in the treatment of MIGRAINE DISORDERS and tremor.
A visual symptom in which a single object is perceived by the visual cortex as two objects rather than one. Disorders associated with this condition include REFRACTIVE ERRORS; STRABISMUS; OCULOMOTOR NERVE DISEASES; TROCHLEAR NERVE DISEASES; ABDUCENS NERVE DISEASES; and diseases of the BRAIN STEM and OCCIPITAL LOBE.
A superficial, epithelial Herpesvirus hominis infection of the cornea, characterized by the presence of small vesicles which may break down and coalesce to form dendritic ulcers (KERATITIS, DENDRITIC). (Dictionary of Visual Science, 3d ed)
Surgery performed on the eye or any of its parts.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Echocardiography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image.
Proteins obtained from the ZEBRAFISH. Many of the proteins in this species have been the subject of studies involving basic embryological development (EMBRYOLOGY).
The concave interior of the eye, consisting of the retina, the choroid, the sclera, the optic disk, and blood vessels, seen by means of the ophthalmoscope. (Cline et al., Dictionary of Visual Science, 4th ed)
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
A surgical specialty concerned with the structure and function of the eye and the medical and surgical treatment of its defects and diseases.
Analogs or derivatives of prostaglandins F that do not occur naturally in the body. They do not include the product of the chemical synthesis of hormonal PGF.
Congenital anomaly in which some of the structures of the eye are absent due to incomplete fusion of the fetal intraocular fissure during gestation.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
Tumors or cancer of the CONJUNCTIVA.
Set of cell bodies and nerve fibers conducting impulses from the eyes to the cerebral cortex. It includes the RETINA; OPTIC NERVE; optic tract; and geniculocalcarine tract.
An oval, bony chamber of the inner ear, part of the bony labyrinth. It is continuous with bony COCHLEA anteriorly, and SEMICIRCULAR CANALS posteriorly. The vestibule contains two communicating sacs (utricle and saccule) of the balancing apparatus. The oval window on its lateral wall is occupied by the base of the STAPES of the MIDDLE EAR.
The lectin wheatgerm agglutinin conjugated to the enzyme HORSERADISH PEROXIDASE. It is widely used for tracing neural pathways.
Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). (Dorland, 27th ed)
Geological formations consisting of underground enclosures with access from the surface.
The total area or space visible in a person's peripheral vision with the eye looking straightforward.
The four cellular masses in the floor of the fourth ventricle giving rise to a widely dispersed special sensory system. Included is the superior, medial, inferior, and LATERAL VESTIBULAR NUCLEUS. (From Dorland, 27th ed)
The pigmented vascular coat of the eyeball, consisting of the CHOROID; CILIARY BODY; and IRIS, which are continuous with each other. (Cline et al., Dictionary of Visual Science, 4th ed)
Injury to any part of the eye by extreme heat, chemical agents, or ultraviolet radiation.
The tear-forming and tear-conducting system which includes the lacrimal glands, eyelid margins, conjunctival sac, and the tear drainage system.
The 3d cranial nerve. The oculomotor nerve sends motor fibers to the levator muscles of the eyelid and to the superior rectus, inferior rectus, and inferior oblique muscles of the eye. It also sends parasympathetic efferents (via the ciliary ganglion) to the muscles controlling pupillary constriction and accommodation. The motor fibers originate in the oculomotor nuclei of the midbrain.
Involuntary rhythmical movements of the eyes in the normal person. These can be naturally occurring as in end-position (end-point, end-stage, or deviational) nystagmus or induced by the optokinetic drum (NYSTAGMUS, OPTOKINETIC), caloric test, or a rotating chair.
A form of herpetic keratitis characterized by the formation of small vesicles which break down and coalesce to form recurring dendritic ulcers, characteristically irregular, linear, branching, and ending in knoblike extremities. (Dictionary of Visual Science, 3d ed)
Inflammation of the iris characterized by circumcorneal injection, aqueous flare, keratotic precipitates, and constricted and sluggish pupil along with discoloration of the iris.
Area of the OCCIPITAL LOBE concerned with the processing of visual information relayed via VISUAL PATHWAYS.
Inflammation of the anterior uvea comprising the iris, angle structures, and the ciliary body. Manifestations of this disorder include ciliary injection, exudation into the anterior chamber, iris changes, and adhesions between the iris and lens (posterior synechiae). Intraocular pressure may be increased or reduced.
A species of the genus MACACA which typically lives near the coast in tidal creeks and mangrove swamps primarily on the islands of the Malay peninsula.
Simultaneous inflammation of the cornea and conjunctiva.
Infection by a variety of fungi, usually through four possible mechanisms: superficial infection producing conjunctivitis, keratitis, or lacrimal obstruction; extension of infection from neighboring structures - skin, paranasal sinuses, nasopharynx; direct introduction during surgery or accidental penetrating trauma; or via the blood or lymphatic routes in patients with underlying mycoses.
The absence or restriction of the usual external sensory stimuli to which the individual responds.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.
Congenital or developmental anomaly in which the eyeballs are abnormally small.
Disorder occurring in the central or peripheral area of the cornea. The usual degree of transparency becomes relatively opaque.
Inanimate objects that become enclosed in the eye.
Artery originating from the internal carotid artery and distributing to the eye, orbit and adjacent facial structures.
Substances added to pharmaceutical preparations to protect them from chemical change or microbial action. They include ANTI-BACTERIAL AGENTS and antioxidants.
The blood vessels which supply and drain the RETINA.
Voluntary or involuntary motion of head that may be relative to or independent of body; includes animals and humans.
The sedge plant family of the order Cyperales, subclass Commelinidae, class Liliopsida (monocotyledons)
A species of the genus MACACA inhabiting India, China, and other parts of Asia. The species is used extensively in biomedical research and adapts very well to living with humans.
Pieces of glass or other transparent materials used for magnification or increased visual acuity.
The part of the brain that connects the CEREBRAL HEMISPHERES with the SPINAL CORD. It consists of the MESENCEPHALON; PONS; and MEDULLA OBLONGATA.
Conjunctivitis due to hypersensitivity to various allergens.
The adjustment of the eye to variations in the intensity of light. Light adaptation is the adjustment of the eye when the light threshold is increased; DARK ADAPTATION when the light is greatly reduced. (From Cline et al., Dictionary of Visual Science, 4th ed)
The surgical removal of the eyeball leaving the eye muscles and remaining orbital contents intact.
Inflammation, often mild, of the conjunctiva caused by a variety of viral agents. Conjunctival involvement may be part of a systemic infection.
A chronic infection of the CONJUNCTIVA and CORNEA caused by CHLAMYDIA TRACHOMATIS.
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
Methods and procedures for the diagnosis of diseases of the eye or of vision disorders.
Inflammation of the choroid.
A reflex wherein impulses are conveyed from the cupulas of the SEMICIRCULAR CANALS and from the OTOLITHIC MEMBRANE of the SACCULE AND UTRICLE via the VESTIBULAR NUCLEI of the BRAIN STEM and the median longitudinal fasciculus to the OCULOMOTOR NERVE nuclei. It functions to maintain a stable retinal image during head rotation by generating appropriate compensatory EYE MOVEMENTS.
Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of EYE DISEASES; OPTIC NERVE DISEASES; OPTIC CHIASM diseases; or BRAIN DISEASES affecting the VISUAL PATHWAYS or OCCIPITAL LOBE.
Method of making images on a sensitized surface by exposure to light or other radiant energy.
Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Use of electric potential or currents to elicit biological responses.
Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.
The time from the onset of a stimulus until a response is observed.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
The 6th cranial nerve which originates in the ABDUCENS NUCLEUS of the PONS and sends motor fibers to the lateral rectus muscles of the EYE. Damage to the nerve or its nucleus disrupts horizontal eye movement control.
Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
Inflammation of the RETINA. It is rarely limited to the retina, but is commonly associated with diseases of the choroid (CHORIORETINITIS) and of the OPTIC DISK (neuroretinitis).
Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.
Acetanilide derivative used as a local anesthetic.
Central retinal artery and its branches. It arises from the ophthalmic artery, pierces the optic nerve and runs through its center, enters the eye through the porus opticus and branches to supply the retina.
Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.
Computer-assisted study of methods for obtaining useful quantitative solutions to problems that have been expressed mathematically.
A refractive error in which rays of light entering the eye parallel to the optic axis are brought to a focus behind the retina, as a result of the eyeball being too short from front to back. It is also called farsightedness because the near point is more distant than it is in emmetropia with an equal amplitude of accommodation. (Dorland, 27th ed)
A genus of the subfamily CERCOPITHECINAE, family CERCOPITHECIDAE, consisting of 16 species inhabiting forests of Africa, Asia, and the islands of Borneo, Philippines, and Celebes.
Act of eliciting a response from a person or organism through physical contact.
An annular transitional zone, approximately 1 mm wide, between the cornea and the bulbar conjunctiva and sclera. It is highly vascular and is involved in the metabolism of the cornea. It is ophthalmologically significant in that it appears on the outer surface of the eyeball as a slight furrow, marking the line between the clear cornea and the sclera. (Dictionary of Visual Science, 3d ed)
In statistics, a technique for numerically approximating the solution of a mathematical problem by studying the distribution of some random variable, often generated by a computer. The name alludes to the randomness characteristic of the games of chance played at the gambling casinos in Monte Carlo. (From Random House Unabridged Dictionary, 2d ed, 1993)
The use of statistical and mathematical methods to analyze biological observations and phenomena.
Set of nerve fibers conducting impulses from olfactory receptors to the cerebral cortex. It includes the OLFACTORY NERVE; OLFACTORY BULB; OLFACTORY TRACT; OLFACTORY TUBERCLE; ANTERIOR PERFORATED SUBSTANCE; and OLFACTORY CORTEX.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The distance between the anterior and posterior poles of the eye, measured either by ULTRASONOGRAPHY or by partial coherence interferometry.
A ready-made or custom-made prosthesis of glass or plastic shaped and colored to resemble the anterior portion of a normal eye and used for cosmetic reasons. It is attached to the anterior portion of an orbital implant (ORBITAL IMPLANTS) which is placed in the socket of an enucleated or eviscerated eye. (From Dorland, 28th ed)
Part of the DIENCEPHALON inferior to the caudal end of the dorsal THALAMUS. Includes the lateral geniculate body which relays visual impulses from the OPTIC TRACT to the calcarine cortex, and the medial geniculate body which relays auditory impulses from the lateral lemniscus to the AUDITORY CORTEX.
Recording of the average amplitude of the resting potential arising between the cornea and the retina in light and dark adaptation as the eyes turn a standard distance to the right and the left. The increase in potential with light adaptation is used to evaluate the condition of the retinal pigment epithelium.
Inflammation in which both the anterior and posterior segments of the uvea are involved and a specific focus is not apparent. It is often severe and extensive and a serious threat to vision. Causes include systemic diseases such as tuberculosis, sarcoidosis, and syphilis, as well as malignancies. The intermediate segment of the eye is not involved.
A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.
Large herbivorous tropical American lizards.
Substances used to identify the location and to characterize the types of NEURAL PATHWAYS.
Recording of nystagmus based on changes in the electrical field surrounding the eye produced by the difference in potential between the cornea and the retina.
The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.
NEURAL PATHWAYS and connections within the CENTRAL NERVOUS SYSTEM, beginning at the hair cells of the ORGAN OF CORTI, continuing along the eighth cranial nerve, and terminating at the AUDITORY CORTEX.
Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
The portion of the optic nerve seen in the fundus with the ophthalmoscope. It is formed by the meeting of all the retinal ganglion cell axons as they enter the optic nerve.
Cellular receptors which mediate the sense of temperature. Thermoreceptors in vertebrates are mostly located under the skin. In mammals there are separate types of thermoreceptors for cold and for warmth and NOCICEPTORS which detect cold or heat extreme enough to cause pain.
Visualization of a vascular system after intravenous injection of a fluorescein solution. The images may be photographed or televised. It is used especially in studying the retinal and uveal vasculature.
The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.
Ocular disorders attendant upon non-ocular disease or injury.
Personal devices for protection of the eyes from impact, flying objects, glare, liquids, or injurious radiation.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Loss of epithelial tissue from the surface of the cornea due to progressive erosion and necrosis of the tissue; usually caused by bacterial, fungal, or viral infection.

Dynamics of horizontal vergence movements: interaction with horizontal and vertical saccades and relation with monocular preferences. (1/314)

We studied the dynamics of pure vergence shifts and vergence shifts combined with vertical and horizontal saccades. It is known from earlier studies that horizontal saccades accelerate horizontal vergence. We wanted to obtain a more complete picture of the interactions between version and vergence. Therefore we studied pure version (horizontal and vertical), pure vergence (divergence and convergence) and combinations of both in five adult subjects with normal binocular vision and little phoria (< 5 degrees). The visual targets were LED's in isovergence arrays presented at two distances (35 and 130 cm) in a dimly lit room. Two targets were continuously lit during each trial and gaze-shifts were paced by a metronome. The two subjects with a strong monocular preference made vergence eye movements together with small horizontal saccades during pure vergence tasks. The other subjects, who did not have a strong monocular preference, made pure vergence movements (without saccades). These findings, suggest that monocular preferences influence the oculomotor strategy during vergence tasks. Vergence was facilitated by both horizontal and vertical saccades but vergence peak-velocity during horizontal saccades was higher than during vertical saccades.  (+info)

Perturbation of combined saccade-vergence movements by microstimulation in monkey superior colliculus. (2/314)

Perturbation of combined saccade-vergence movements by microstimulation in monkey superior colliculus. This study investigated the role of the monkey superior colliculus (SC) in the control of visually (V)-guided combined saccade-vergence movements by assessing the perturbing effects of microstimulation. We elicited an electrical saccade (E) by stimulation (in 20% of trials) in the SC while the monkey was preparing a V-guided movement to a near target. The target was aligned such that E- and V-induced saccades had similar amplitudes but different directions and such that V-induced saccades had a significant vergence component (saccades to a near target). The onset of the E-stimulus was varied from immediately after V-target onset to after V-saccade onset. E-control trials, where stimulation was applied during fixation of a V-target, yielded the expected saccade but no vergence. By contrast, early perturbation trials, where the E-stimulus was applied soon after the onset of the V-target, caused an E-triggered response with a clear vergence component toward the V-target. Midflight perturbation, timed to occur just after the monkey initiated the movement toward the target, markedly curtailed the ongoing vergence component during the saccade. Examination of pooled responses from both types of perturbation trials showed weighted-averaging effects between E- and V-stimuli in both saccade and fast vergence components. Both components exhibited a progression from E- to V-dominance as the E-stimulus was delayed further. This study shows that artificial intervention in the SC, while a three-dimensional (3D) refixation is being prepared or is ongoing, can affect the timing (WHEN) and the metric specification (WHERE) of both saccades and vergence. To explain this we interpret the absence of overt vergence in the E-controls as being caused by a zero-vergence change command rather than reflecting the mere absence of a collicular vergence signal. In the perturbation trials, the E-evoked zero-vergence signal competes with the V-initiated saccade-vergence signal, thereby giving rise to a compromised 3D response. This effect would be expected if the population of movement cells at each SC site is tuned in 3D, combining the well-known topographical code for direction and amplitude with a nontopographical depth representation. On E-stimulation, the local population would yield a net saccade signal caused by the topography, but the cells coding for different depths would be excited equally, causing the vergence change to be zero.  (+info)

Instability of torsion during smooth asymmetric vergence. (3/314)

Several categories of torsional eye movements obey Listing's law; however, systematic deviations from this law occur during vergence. Two kinematic models attempt to incorporate these deviations, both of which are supported by experimental evidence; however, they lead to different torsion predictions. These discrepancies have been explained in terms of experimental procedures, but it now seems likely from several recent studies that individual differences in torsion patterns may also be important. This study therefore examines the variation of torsion during a smooth asymmetric vergence task in which a fixation target was moved along the line-of-sight of the right eye at 15 degrees elevation; each of five subjects observed five trials of both inward and outward target motion, repeated in two sessions several weeks apart. There were no significant group differences in left or right eye torsion between trials or sessions, suggesting that monocular torsion patterns were relatively stable over time. When examined more closely, however, the torsion patterns shown by some individuals did vary for inward versus outward target motion. Hence, monocular torsion was idiosyncratic and depended on the direction in which fixation was changing (convergence or divergence). In a binocular analysis, cycloversion varied dramatically between subjects and depended on the direction of target motion; however, this was not the case for cyclovergence. In summary, cyclovergence is relatively stable and depends on where the eyes are looking, whereas cycloversion (and hence monocular torsion) is relatively unstable and depends on how they came to be in that particular horizontal and vertical orientation. These findings help to explain the controversy surrounding the torsional behaviour of the human eye during vergence.  (+info)

The effect of target size and eccentricity on reflex disparity vergence. (4/314)

This study examined the effects of stimulus size and eccentricity on reflex disparity vergence: the small, involuntary corrections of eye alignment which serve to minimize the binocular disparity of fixated targets. Subjects were instructed to fixate steadily on a small, stationary mark superimposed on the center of a dynamic random dot stereogram. The stereogram was binocularly uncorrelated except for a fully correlated patch whose size and eccentricity were varied systematically across trials. The disparity of the patch was varied sinusoidally over time to stimulate vergence following movements. The overall purpose was to determine the relative contributions of various field loci in controlling binocular fixation by finding the smallest patch which would reliably drive vergence against the effort to fixate steadily. Psychophysical thresholds for detection of the correlated patch stimuli were also measured for comparison to the oculomotor results. Results showed that the smallest effective patch increased with eccentricity similarly for both vergence responses and psychophysical detection, suggesting they depend on a common, presumably cortical matching process. The dependence of response on eccentricity is roughly consistent with changes in the cortical magnification factor, suggesting that the area of cortex stimulated may be the determining factor in vergence responses to this class of stimulus.  (+info)

Orientation and luminance polarity tuning of the transient-vergence system. (5/314)

Previously, Edwards, Pope & Schoor, Vision Research, 38, 705-717, demonstrated that transient disparity vergence appears to be mediated by a system that employs a single low-pass sensitive spatial channel whose performance is not reduced by dichoptic mixed contrasts (no contrast paradox) or dichoptic mixed spatial frequencies. This broadband tuning to both contrast and spatial frequency may be indicative of a second-order or non-linear envelope extraction system. The current study tests for lack of tuning to orientation and luminance polarity which are typically taken as evidence of a second-order system. We found that when the transient vergence system was simultaneously presented with both convergent and divergent disparities, there was a small but distinct bias in favor of responding in the direction defined by matched orientations or luminance polarities over unmatched pairs. Although less frequent, responses to orthogonal carriers or opposite luminance polarities were possible. The vergence system could match a horizontal with a vertical carrier, or a light gaussian with a dark gaussian. The degree of orientation or luminance polarity tuning varied inversely with the disparity magnitude over the range of 2.5-5 degrees, and the orientation tuning peaked at a spatial frequency about 2 cpd. At all disparities tested, however, the tuning was very broad, and other candidate features for mediating transient-vergence need to be investigated.  (+info)

Fixation disparity and nonius bias. (6/314)

Fixation disparity, i.e. the vergence error within Panum's area, can be measured psychophysically with two nonius (vernier) lines that are presented dichoptically, i.e. one to each eye. The observer adjusts these nonius lines to subjective alignment; the resulting physical nonius offset indicates the amount of fixation disparity. The present experiments investigate the relation between fixation disparity and the nonius bias, which is the physical offset of the nonius lines that is adjusted by the observer in order to perceive them as aligned when both nonius lines are presented to both eyes (binocular nonius bias) or both to the left or both to the right eye (monocular nonius bias). It was found that (1) the fixation disparity is correlated with the binocular nonius bias in the horizontal and vertical meridian and (2) the binocular nonius bias can be predicted from the average of the right eye and left eye monocular nonius bias. To remove the influence of the nonius bias on measured fixation disparity it is possible to calculate the fixation disparity relative to the individual binocular nonius bias, rather than to the physical coincidence of the nonius lines. This procedure tends to increase the correlation between fixation disparity and the tonic resting position of vergence. We discuss the clinical relevance of the dichoptic nonius method for measuring fixation disparity and its limitations as compared to physical recordings of eye position.  (+info)

Characteristics of accommodation toward apparent depth. (7/314)

This paper deals with characteristics of accommodation evoked by perceived depth sensation and the dynamic relationship between accommodation and vergence, applying newly developed optical measurement apparatuses. A total of five subjects looked at three different two-dimensional stimuli and two different three-dimensional stimuli; namely a real image and a stereoscopic image. With regard to the two-dimensional stimuli, a manifest accommodation without any accompanying vergence was found because of an apparent depth sensation even though the target distance was kept constant. With regard to the three-dimensional stimuli, larger accommodation and clear vergence were evoked because of binocular parallax and a stronger depth sensation. As for the stereoscopic image, a manifest overshoot (the accommodation peaked first and receded considerably) was found while the vergence remained constant. On the other hand, the overshoot of accommodation was smaller when subjects were watching the real image. These results reveal that brain depth perception has a higher effect on accommodation than expected. The relationship of accommodation and vergence toward the stereoscopic image suggests a reason why severe visual fatigue is commonly experienced by many viewers using stereoscopic displays. It has also paved the way for the numerical analysis of the oculomotor triad system.  (+info)

Stereopsis, cyclovergence and the backwards tilt of the vertical horopter. (8/314)

It is generally recognized that the vertical horopter has a backwards tilt such that it passes through the fixation point and a point near the feet of the observer. The basis of the tilt has been attributed to either a shear in binocular retinal correspondence along the vertical meridian or the presence of cyclovergence eye movements. In an attempt to determine empirically the mechanisms underlying the tilt of the vertical horopter, retinal correspondence along the vertical meridian was investigated as a function of viewing distance. In addition, binocular measurements of torsional eye position were made in the same observers under similar viewing conditions. The vertical horopter was determined using two criteria. In the first instance, increment depth discrimination thresholds for both crossed and uncrossed disparities were measured as a function of retinal eccentricity along the vertical meridian, up to 5 degrees superiorly and inferiorly, and the horopter was defined by the region in space which had the lowest stereo-threshold. Secondly, subjective alignment of dichoptically presented nonius lines defined the horopter by identical visual directions. Both criteria were used to determine the horopter at 2 m while only the criterion of identical visual direction was used at the nearer distance of 50 cm. The vertical horopter showed a backwards tilt that decreased from an average of about 12 degrees at 2 m to 3 degrees at 50 cm, with some variability between observers. Torsional eye position did not change significantly between fixation distances. These results confirmed the geometric relation between the backwards tilt in the vertical horopter and fixation distance and support Helmholtz's original contention that the tilt is a consequence of a shear in retinal correspondence in the vertical meridian.  (+info)

Definition of Unit of ocular convergence with photos and pictures, translations, sample usage, and additional links for more information.
This study was designed to determine how the developing visual system weights retinal blur and disparity in generating accommodative and vergence responses when both cues are present, as is the case under naturalistic binocular viewing conditions. Blur and disparity cues were placed in conflict with each other and the impact of this cue-conflict on accommodative and vergence performance was assessed across a wide range of ages (2.0 months to 40.8 years). Three hypothetical patterns of results were derived for Experiments 1 and 2 to provide insights into the relative use of the two cues. The data indicated that, when directly stimulated with lenses or prisms, both accommodation and vergence responded, although inaccurately, with the frequencies and amplitudes of vergence responses being slightly larger than those of the accommodative responses across all ages tested ( Table 2, Figure 5, panel a). The mean accommodative response for the −2 D lens stimulus was 1.18 D ( SEM = 0.42 D) (a mean ...
Neuropsychology examines the relationship between cognitive activity and corresponding cerebral conditions. At one end, psychophysics meticulously describes the details of behavior. At the other, physiology records brain cell activity during cognitive tasks. Bridging the two, neuropsychology establishes the neural correlate of behaviour when correlation methods are used, and extends to the critical neural substrate when a causal relationship can be established. Here we revisit the Hering-versus-Helmholtz controversy on binocular coordination from the psychophysicians description of combined saccade-vergence eye movements to the neurophysiological recording of motor and premotor neurons of the oculomotor neural circuitry. Whilst neo-Heringian psychophysicians and physiologists have accumulated arguments for separate saccade and vergence systems, at both the behavioral and the neural premotor levels, neo-Helmholtzians have also provided evidence for monocular programmed eye movements and commands ...
This paper presents an architecture for computing vector disparity for active vision systems as used on robotics applications. The control of the vergence angle of a binocular system allows us to efficiently explore dynamic environments, but requires a generalization of the disparity computation with respect to a static camera setup, where the disparity is strictly 1-D after the image rectification. The interaction between vision and motor control allows us to develop an active sensor that achieves high accuracy of the disparity computation around the fixation point, and fast reaction time for the vergence control. In this contribution, we address the development of a real-time architecture for vector disparity computation using an FPGA device. We implement the disparity unit and the control module for vergence, version, and tilt to determine the fixation point. In addition, two on-chip different alternatives for the vector disparity engines are discussed based on the luminance (gradient-based) and
Purpose: Vergence movements are slow disconjugate eye movements which may be triggered by image disparity or accommodation. There exist numerous clinical contexts where image disparity may vary with the direction of gaze. A common example is a sixth cranial nerve palsy with increasing image disparity in gaze toward the affected muscle. Adaptive changes to such incomitant image disparity have been poorly investigated and are the scope of this study.. Methods: Vergence stimuli of gaze dependent magnitude were used to mimic the image disparity of an incomitant strabismus. In a first experiment prisms were placed such that stimuli were viewed through the prisms in one gaze direction but not in the other gaze directions. In a second experiment we used a haploscope to modify image disparity according to gaze. We measured vergence responses that were made after a saccade shifting gaze from left to right, with increased image disparity in right gaze. We analysed changes of rise time or slope, latency, ...
Fusional vergence is the movement of both eyes that enables the fusion of monocular images producing binocular vision. It is especially important when a person has heterophoria. Premotor cells for fusional vergence are located in the mesencephalon near the oculomotor nucleus ...
Purpose: Accurate accommodation and vergence are required to achieve optimal image quality and single vision. Abnormal visual experience disrupts visual development and therefore accommodation and vergence are central in promoting normal visual development during infancy and childhood. The systems are also neurally coupled and hyperopic children are at risk for over-convergence and strabismus. It is not yet possible to predict which infants will develop this strabismus and the goal of this study was to develop a model to understand the interaction in the coupling. Methods: Several groups have developed related models of accommodation and vergence interactions in adults (Westheimer, 1963; Schor, 1985; Hung, 1997). These models were adapted to examine the developmental implications, incorporating recent data collected from 3-6 month-old infants, 2-4 year-old children, and adults. The model parameters included refractive error, interpupillary distance, and AC/A and CA/C ratios. Results: For a ...
The subjects wore glass-formed crossed polarizers and faced a large (45.6° × 35.0°) translucent tangent screen placed at 2 m distance, on which a two-frame movie was back-projected from two liquid crystal display (LCD) projectors through crossed polarizers. Visual stimuli were controlled by a personal computer through an image-processing board (model CT-3000A; Cybertec, Osaka, Japan). The room was dark except for the target lights. The central disparity target was a vertical bar (2.5° high × 1.4° wide), which always jumped from a distance of 2 to 1 m, but the interval between target jumps was randomized between 1.5 and 3.5 seconds. The peripheral disparity target was a random-dot pattern, with density textured blobs subtending 0.4° at 2 m that were correlated between two eyes and with a luminance that ranged from 20 cd/m2 (white dots) to 0.1 cd/m2 (blank area). The peripheral disparity target contained a central blank square that was 10° × 10°, 20° × 20°, or 30° × 30°. The ...
Recordings of the horizontal component of movements of the eyes were made during monocular and binocular fixation. The variation in the vergence of the eyes over time was found to be of the same order of magnitude as the variation in position of the individual eyes, even though the lateral positions of the two eyes are somewhat correlated. The drift and tremor of the two eyes are not correlated; the over-all correlation is due to the saccadic movements. Saccades in one eye seem to be always accompanied by simultaneous saccades in the other eye which are almost always in the same direction and about the same in size. The maintenance of binocular fixation does not seem to be dependent on a direct response to or sensing of vergence error. Rather, it appears to be dependent on the saccadic responses of the two eyes to their own fixation errors.. © 1960 Optical Society of America. Full Article , PDF Article ...
Convergence excess is a condition in which a childs eyes have a tendency to aim closer than the object, which the child is trying to see. It is possible to achieve correct aim only by exerting extra effort (Figure 1). Prolonged periods of close work can cause considerable discomfort.. Many cases of convergence excess are due to long-sightedness. The need which longsighted people have to exert extra focusing (accommodation) to see clearly at close range has the effect of making the eyes tend to turn in too far, which creates the convergence excess.. Convergence excess affects about ten per cent of school children. It is less common in adults.. Convergence excess can be treated with the use of reading glasses (or bifocals), which relax the convergence and focusing systems, thus removing the need for extra effort.This often allows longer and more efficient concentration on close tasks. Eye exercises are not usually successful in treating convergence excess ...
Researchers are now calling for the preoperative evaluation of surgical patients seeking spectacle/contact lens independence to include a complete binocular and accommodation assessment after finding such issues could develop post-op. While they found corneal refractive surgery was not a relevant source of binocular/accommodative problems, most of the issues that arose after refractive and cataract surgery turned out to be preexisting conditions or dysfunctions. Thorough preoperative screening evaluations would help to identify dysfunctional eyes prone to destabilization after surgery that could potentially develop asthenopic symptoms.. The review included 95 works selected from 40 publications. A decrease in fusional vergence amplitude in near vision was the most frequently reported alteration. Other alterations were less common and were transient in most of the cases. The researchers suggested that, for binocular vision complaints, all treatment decisions must be postponed until at least three ...
X-List-Received-Date: Sun, 20 Jun 2004 02:34:02 -0000 This is a multi-part message in MIME format. ------_PartID_841078126725317 Content-Type: text/plain; charset=WINDOWS-1256 Content-Transfer-Encoding: quoted-printable =C7=E1=E3=CF=ED=E4=C9 =E3=C7=D1=DF=CA - =C3=D6=CE=E3 =C8=E6=C7=C8=C9 =C7=E1=DF=CA=D1=E6=E4=ED=C9 =D3=DA=E6=CF=ED=C9 =CA=DA=D1=ED=DD =DA=DC=DC=DC=DC=DC=DC=DC=C7=E3 =C8=C7=E1=E3=E6=DE=DA : =ED=DA=CA=C8=D1 =C7=E1=E3=E6=DE=DA =C7=E1=C8=E6=C7=C8=C9 =C7=E1=C7=E1=DF=CA=D1=E6=E4=ED=C9 =C7=E1=D3=DA=E6=CF=ED=C9 =C7=E1=C3=E6=E1=EC =E6 =C7=E1=D0=ED =ED=CD=CA=E6=ED =CC=E3=ED=DA =C7=E1=E4=D4=C7=D8=C7=CA =E6 =C7=E1=CE=CF=E3=C7=CA =E3=D5=E4=DD=C9 =CD=D3=C8 =C7=E1=E3=CF=E4 =C7=E1=D3=DA=E6=CF=ED=C9 =E6 =ED=CA=E3=CA=DA =E5=D0=C7 =C7=E1=E3=E6=DE=DA =C8=E3=D2=C7=ED=C7 =DA=CF=ED=CF=C9 =E1=C7 =CA=CA=E6=DD=D1 =DD=ED =CC=E3=ED=DA =C7=E1=E3=E6=C7=DE=DA =C7=E1=E3=E3=C7=CB=E1=C9 . =C3=E5=E3 =E3=DF=E6=E4=C7=CA =C7=E1=E3=E6=DE=DA : 1- =C7=E1=C5=DA=E1=C7=E4=C7=CA =C7=E1=E3=CC=C7=E4=ED=C9 : =ED=E6=DD=D1 ...
Convergence refers to the development of similar characteristics or adaptations in animals that differ in direct ancestry. Parallelism implies a similarity in biological makeup of the ancestral forms, whereas convergence does not.
trend line and convergence forex cci - trend line and convergence forex cci, forex concept diagram, tradestation forex costs, kg daily forex analysis
phorias are a common cause of headaches amongVDU users). - Central-field defects (blind spots). - Near point of convergence - Clarity (ie no scarring of the lensor cornea). ...
The ADP1851 is a wide range input, dc-to-dc, synchronousbuck controller capable of running from commonly used 3.3 Vto 12 V (up to 20 V) voltage inputs. The device nominallyoperates in current mode with valley current sensing providingthe fastest step response for digital loads. It can also be configured as a voltage mode controller with low noise a
Moving average convergence divergence (MACD), invented in 1979 by Gerald Appel, is one of the most popular technical indicators in trading. The MACD is appreciated by traders the world over for ...
TEDxYaba, an independently organized TED event dedicated to fostering Pan-African ideas has announced its major TEDx event of the year, tagged CONVERGENCE
Information and registration here. The Convergence Forum brings together high-level healthcare players to discuss and debate the most pressing topics of in
Convergence plot of the network for an array of 100 cells starting from random uniformly distributed binary initial conditions, 0/black or 1/white for ntcA, het
Im not even sure the sum is right since I didnt write anything down for i. Is using the MGF the way to go or should I go back to the definition or use some other method ...
Third-party logistics providers (3PLs) are transforming themselves into businesses that provide a diverse array of services well beyond logistics.
TY - JOUR. T1 - A comparative analysis of vertical and horizontal fixation disparity in sentence reading.. AU - Jainta, Stephanie. AU - Blythe, Hazel. AU - Nikolova, Mirela. AU - Jones, M.O.. AU - Liversedge, Simon. PY - 2015/5/1. Y1 - 2015/5/1. N2 - Humans have two, frontally placed eyes and during reading oculomotor and sensory processes are needed to combine the two inputs into a unified percept of the text. Generally, slight vergence errors, i.e., fixation disparities, occur but do not cause double vision since disparate retinal inputs fall into Panums fusional area, that is, a range of disparity wherein sensory fusion of the two retinal images is achieved. In this study, we report benchmark data with respect to the mean magnitude and range of vertical compared to horizontal fixation disparities for natural reading. Our data clearly fit to an elliptical pattern of Panums fusional area that corresponds with theoretical estimates. Furthermore, when we examined disparity-driven vergence ...
This page is in development! Target vergence demands (in prism diopters) varies for each exercise. symptoms such as headaches, eye strain, blurred vision and double vision -this is called Convergence Insufficiency. Guidelines for Eye Exercises. But for people with symptoms, treatment with eye-focusing exercises can increase the eyes convergence ability. Weakness of convergence can be improved by exercises. Convergence and Divergence, which is the ability of the eyes to move inward and outward so as to focus on an object that moves far and near. Convergence and divergence exercises build accurate eye alignment and sensory fusion. Divergence Insufficiency and Divergence Excess describe a difficulty in the ability to point both eyes at a distance target, like a the board at school or a TV screen. Convergence insufficiency is a difficulty or inability of the eyes to converge and work together at a near distance for extended periods of time, such as when reading, writing, drawing, or viewing a ...
A vertical heterophoria is a vertical misalignment of the eyes. A vertical phoria means that the eyes are aligned with both eyes viewing, but when one eye is covered, the covered eye drifts up or down. A phoria is not the same thing as a tropia. A tropia means that the eyes are looking in different directions, with eyes open as well.. The presence of a vertical phoria has been found to be associated with symptoms of motion sickness. Vertical phorias may also cause symptoms of double vision, head tilt, and eyestrain. A recent study found that correcting for the vertical heterophoria with spectacle prisms reduced symptoms of motion sickness in 50% of patients. (Jackson and Bedell, 2012). Vertical phoria is also associated with concussion and a variety of other illnesses. ...
Listings law, named after German mathematician Johann Benedict Listing (1808-1882), describes the three-dimensional orientation of the eye and its axes of rotation. Listings law has been shown to hold when the head is stationary and upright and gaze is directed toward far targets, i.e., when the eyes are either fixating, making saccades, or pursuing moving visual targets. Listings law (often abbreviated L1) has been generalized to yield the binocular extension of Listings law (often abbreviated L2) which also covers vergence. Listings law states that the eye does not achieve all possible 3D orientations and that, instead, all achieved eye orientations can be reached by starting from one specific primary reference orientation and then rotating about an axis that lies within the plane orthogonal to the primary orientations gaze direction (line of sight / visual axis). This plane is called Listings plane. It can be shown that Listings law implies that, if we start from any chosen eye ...
Strabismus research papers by Christopher W. Tyler. Topics include brain injury, human vergence dynamics, visual function, binocular facilitation, trauma…
Conventional stereoscopic three-dimensional displays suffer from vergence- accommodation conflict because the stimulus to accommodation is fixed by the display panel and viewing optics, but that to vergence changes with image contents. With the recent rapid development of head-mounted displays, several methods have been proposed to offer the accommodation cues, among which multifocal display technology is an effective and practical solution. The first two decades of this century has witnessed the fast growth of multifocal displays from basic concept to mature implementations. This review systematically presents the state-of-the-art multifocal display design and development. Firstly, a comprehensive classification of numerous potential optical architectures to provide the multiplanar functionality is introduced, based on how the information is multiplexed and how the focal planes are generated. Next, the strengths and obstacles of reported or potential designs in each category are analyzed and compared
Psychology definition for Placebo Therapy in normal everyday language, edited by psychologists, professors and leading students. Help us get better.
Downloadable! In this paper we develop flexible techniques for measuring the speed of output convergence between countries when such convergence may be of an unknown non-linear form. We then calculate these convergence speeds for various countries, in terms of half-lives, from two time-series data-sets. These calculations are based on both nonparametric kernel regression and fuzzy regression, and the results are compared with more restrictive estimates based on the assumption of linear convergence. The calculated half-lives are regressed, again in various flexible ways, on cross-section data for the degree of openness to trade. We find evidence that favours the hypothesis that increased trade openness is associated with a faster rate of convergence in output between countries.
Downloadable (with restrictions)! This article analyses the consequences of spatial interdependence for convergence in a Solow-type growth model. In such a model a regions speed of convergence depends on its location and it can be decomposed into: (i) the speed of convergence proper, (ii) the remoteness effect, and (iii) the impact of the initial gap. Also &sgr;-convergence is affected by spatial interaction and we propose a decomposition to isolate the impact of spatial spillovers. Using GDP per capita of European regions, we calibrate a numerical model with parameters typically found in spatial convergence studies. We find that the remoteness effect leads to considerable variation in the speed of convergence while it marginally affects &sgr;-convergence. Copyright (c) 2006 the author(s). Journal compilation (c) 2006 RSAI.
Given two series $\sum _{n=1}^{ \infty} a_nz^n$ and $\sum _{n=1}^{ \infty} b_nz^n$ who both have radius of convergence $R$, show that the radius of convergence for $\sum _{n=1}^{ \infty} c_nz^n$ is at least $R$ when $c_n = \sum _{k=0}^{n} a_kb_{n-k}$.. To use the Cauchy-Hadamard Theorem, Im trying to find $\limsup \lvert{c_n}\rvert$. I know that $\limsup \lvert{a_n}\rvert ^{-\frac{1}{n}}=\limsup \lvert{b_n}\rvert ^{-\frac{1}{n}}= R$. Every combination of $a_n*b_n$ is available as $c_n$ so I figured Id try the values of $a_n$ and $b_n$ which are their respective $\limsup$s. This yields a radius of convergence of $R^2$ which is only greater than $R$ for $R\ge1$.. How do I show that the radius of convergence of the series is at least $R$ for $R\lt1$?. ...
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Purchase Guldens Lewerenz Accomodation Maddox. This device features an occluder, Maddox lens, and calibrated scale in both centimeters and diopters. It can be used to measure the Amplitude of Accommodation and Near Point of Convergence.
The convergence properties of four simplified gradient adaptive lattice algorithms are analyzed. First, the convergence models that specify the convergence
We address the problem of analyzing the radius of convergence of perturbative expansion of nonequilibrium steady states of Lindblad-driven spin chains. A simple formal approach is developed for systematically computing the perturbative expansion of small driven systems. We consider the paradigmatic model of an open XXZ spin-1/2 chain with boundary-supported ultralocal Lindblad dissipators and treat two different perturbative cases: (i) expansion in the system-bath coupling parameter and (ii) expansion in the driving (bias) parameter. In the first case (i) we find that the radius of convergence quickly shrinks with increasing the system size, while in the second case (ii) we find that the convergence radius is always larger than 1, and in particular it approaches 1 from above as we change the anisotropy from an easy-plane (XY) to an easy-axis (Ising) regime ...
The European Union is committed to economic, social and territorial cohesion, inclusive growth and upward economic convergence. Monitoring convergence within and between Member States, particularly convergence in living and working conditions, was introduced as strategic area of invention in Eurofounds four-year work programme for 2017-2020.
Aaron: Thanks for the feedback. I purposefully kept the definition of tropia as simple as possible. You are correct, in that you can also have an intermittent tropia. You can also have an alternating tropia, convergence-related tropia, and many other types of tropia/phoria depending upon how you like to name things.. When I put this presentation together, I felt it safer to avoid these nuances. I feared that discussing the intermittent nature of phorias/tropias would muddy the waters for the beginner and make the primary difference (between phoria and tropia) that much harder to grasp. Thus, the definition I used is simplified … but still useful and valid for a beginner. Perhaps Ill go into further detail in a future lecture. Thanks!. Tim Root. ...
Hello!. >I have a problem with convergence. Id like to geometry optimize the 1,4-diaminobenzene anion, using DFT/B3LYP. I had no problems with the cation, though. For the initial guess orbitals I used the ones from the ground state calculation. Could you give me any hints regarding how-to try to improve convergence? Due to computational cost I am using only a cc-pVTZ basis, although I know that the augmented one should be used for ions.... >Thank You for your help/ideas!. >Best regards ...
It Is Also Used For Disinfecting Medical And Surgical productsformedicine Equipment. Near Point of Accommodation: The point that is the closest at which an object.....
Supported Shoulderstand pose offers tons of benefits but only if you practice it safely and properly. Here are tips to help you stay safe and aligned.
The first full week of DCs Convergence event is here, and even though the first tie-in issues for it started last week, this is the point where the event starts being interesting. And if your...
Krieck, Sven; Görls, Helmar; Westerhausen, Matthias (2010). [اصطلاحي تېروتنه: د ناپېژندلې ليکنښې لوښه ۱. Mechanistic Elucidation of the Formation of the Inverse Ca(I) Sandwich Complex [(thf)3Ca(μ-C6H3-1,3,5-Ph3)Ca(thf)3] and Stability of Aryl-Substituted Phenylcalcium Complexes]. Journal of the American Chemical Society 132 (35): 12492-12501. doi:10.1021/ja105534w. PMID 20718434. ...
+ Phụ đề tất cả các phim các bạn vô đây tìm và dow nhé, nhớ gõ tên tiếng E phim và tìm sub nào tên giống với bản phim (HD, DVD, DVDrip...):
1. For each of the sequences whose nth term is given by the formula below (so of course n takes successively the positive integer values 1,2,3...), does it have a limit as n tends to infinity? In each case, briefly explain.
Talk given at CMStatistics 2016 ( The standard methodology for clustering financial time series is quite brittle to …
Here is a video of my keynote address at Mt. Holyoke College: 2012 Global Conference Keynote Speaker Dani Rodrik from MHC MCGI on Vimeo.
A major theme at HIMSS will be the convergence of patient data, social platforms, and analytics -- and what possibilities arise from this convergence.
The main topic here is the disjunctive nature of this constraint. This gave the opportunity of dont-know-nondeterminism by exploring both alternatives in the same time and keeping the result in the domains of the variables. When the alternative is known then the other one is discarded.. The propagation of the constraint. ...
The event will discuss how to complete the European Monetary Union with the help of structural convergence as well as a different fiscal framework and a fiscal capacity.
Kushner BJ (2004). "Ocular torsion: rotations around the 'WHY' axis". J AAPOS. 8 (1): 1-12. doi:10.1016/j.jaapos.2003.09.004. ... Kushner BJ (2005). "The treatment of convergence insufficiency". Arch Ophthalmol. 123 (1): 100-1. doi:10.1001/archopht.123.1. ...
Photoacoustic-guided convergence of light through optically diffusive media. Optics Letters 2011;36(11):2053-2055. Kong F, Chen ... High-resolution photoacoustic imaging of ocular tissues. Ultra Med Biol. 2010;36:733-742. Kong F, Silverman RH, Liu L, Chitnis ... Silverman has explored the use of acoustic radiation force for characterization to ocular tissue properties. He has ... of Ophthalmic Ultrasound and is on the Advisory Boards of the National Institutes of Health Transducer Resource and the Ocular ...
Hyperstereopsis increases ocular convergence and causes near objects to appear closer and with exaggerated depth and slant. IPD ... Other experimental presentations may require the use of IPD to control for ocular convergence and binocular depth. Several ...
... is an eye condition involving inward deviation of the eye, usually due to extra-ocular muscle imbalance. It is a type ... Causes include: Refractive errors Divergence insufficiency Convergence excess; this can be due to nerve, muscle, congenital or ... Eckstein, AK; Fischer, M; Esser, J (1998). "Normal accommodative convergence excess--long-term follow-up of conservative ...
Convergence is the ability of the eye to simultaneously demonstrate inward movement of both eyes toward each other. This is ... Ocular motor control neurons Neurons that are interposed between the afferent and efferent limbs of this circuit and include ... The accommodation reflex (or accommodation-convergence reflex) is a reflex action of the eye, in response to focusing on a near ... "Chapter 7: Ocular Motor System". Neuroscience Online: An Electronic Textbook for the Neurosciences. Department of Neurobiology ...
The over-convergence associated with the extra accommodation required to overcome a hyperopic refractive error can precipitate ... These problems may directly affect the extra-ocular muscles themselves, and may also result from conditions affecting the nerve ... The person with hyperopia, in an attempt to "accommodate" or focus the eyes, converges the eyes as well, as convergence is ... Even though they are exerting a normal amount of accommodative or 'focusing' effort, the amount of convergence associated with ...
... disease Ocular albinism Ocular coloboma-imperforate anus Ocular convergence spasm Ocular histoplasmosis Ocular melanoma Ocular ... motility disorders Ocular toxoplasmosis Oculo-auriculo-vertebral spectrum Oculo cerebral dysplasia Oculo cerebro acral syndrome ...
... convergence by asking patient to report when blur is appreciated progress of a patient undergoing management for ocular ... The divergence amplitude should be measured before convergence, as measuring the convergence amplitude first could contaminate ... Convergence insufficiency - usually associated with accommodative difficulties, the fusional convergence range of these ... Convergence must be measured second to divergence or results will be contaminated. Can only be performed on patients with BSV ...
... convergence, ocular MeSH G11.697.716.260.253 - fixation, ocular MeSH G11.697.716.260.378 - nystagmus, physiologic MeSH G11.697. ... ocular MeSH G11.697.716.154 - adaptation, ocular MeSH G11.697.716.154.371 - dark adaptation MeSH G11.697.716.182 - blinking ... ocular MeSH G11.697.677.330 - evoked potentials, visual MeSH G11.697.677.340 - eye color MeSH G11.697.677.360 - figural ... ocular MeSH G11.697.677.911 - vision MeSH G11.697.677.911.500 - phosphenes MeSH G11.697.677.911.700 - vision, binocular MeSH ...
These letters of the alphabet denote ocular motility pattern that have a similarity to the respective letter: in the A-pattern ... the extra convergence can cause the eyes to cross.[citation needed] During an eye examination, a test such as cover testing or ... Incomitant strabismus is almost always caused by a limitation of ocular rotations that is due to a restriction of extraocular ... or convergence insufficiency. The likelihood was 2.6 times that of controls. No apparent association with premature birth was ...
... eye surface Alteration in the tear film Visual hallucinations Decreased eye convergence Blepharospasm Abnormalities in ocular ... Limitations in upward gaze Blurred vision Diplopia (double vision), produced by a reduced eye convergence. Jankovic J (April ... Gitchel GT, Wetzel PA, Baron MS (2012). "Pervasive ocular tremor in patients with Parkinson disease". Arch Neurol. 69 (8): 1011 ... pursuit, ocular fixation and saccadic movements Difficulties opening the eyelids This can have particular relevance when ...
Accommodation and Convergence of the Eyes (1882) Tests and Studies of the Ocular Muscles (1898) Golden Rules of Refraction ( ...
... paralysis of upward gaze along with several ocular findings such as convergence retraction nystagmus and eyelid retraction also ...
Ocular motility should always be tested, especially when patients complain of double vision or physicians suspect neurologic ... Myopia Hyperopia Presbyopia Amblyopia Diplopia Astigmatism Strabismus Color vision Stereopsis Near point of convergence ... Close inspection of the anterior eye structures and ocular adnexa are often done with a slit lamp which is a table mounted ... The examiner views the illuminated ocular structures, through an optical system that magnifies the image of the eye and the ...
A comprehensive eye examination including an ocular motility (i.e., eye movement) evaluation and an evaluation of the internal ... A common form of exotropia is known as "convergence insufficiency" that responds well to orthoptic vision therapy including ... ocular structures allows an eye doctor to accurately diagnose exotropia. Although glasses and/or patching therapy, exercises, ...
Organic causes may include systemic or ocular medications, brain stem injury, or active ocular inflammation such as uveitis. ... Diplopia: Diplopia may occur due to esotropia or convergence spasm The vision may clear temporarily using concave (minus) ... through eye strain or fatigue of ocular systems. It is common in young adults who have active accommodation, and classically ... or through appropriate ocular exercises. Refraction "Pseudomyopia - symptoms". PSEUDOMYOPIA - false nearsightedness. "Acute ...
The convergence near-point test. The subject fixates an object that is moved toward the nose until divergence of one eye occurs ... Ocular dominance, sometimes called eye preference or eyedness, is the tendency to prefer visual input from one eye to the other ... Ocular dominance column Right- and left-hand traffic Chaurasia BD, Mathur BB (1976). "Eyedness". Acta Anatomica. 96 (2): 301-5 ... Handa T, Mukuno K, Uozato H, Niida T, Shoji N, Minei R, Nitta M, Shimizu K (April 2004). "Ocular dominance and patient ...
Accommodative insufficiency Convergence insufficiency and asthenopia Evaluation of visual issues in education, including ... Pediatric ophthalmologists also have expertise in managing the various ocular diseases that affect children. Pediatric ... a national organization dedicated to improving the quality and management of pediatric ocular disease. Over time, over 30 ... and other physicians refer pediatric patients to a pediatric ophthalmologist for examination and management of ocular problems ...
Scheiman M, Kulp MT, Cotter SA, Lawrenson JG, Wang L, Li T (Dec 2, 2020). "Interventions for convergence insufficiency: a ... French ophthalmologist Louis Emile Javal, began using ocular exercises to treat strabismus (squint) and described the practice ... Bates method Convergence insufficiency Diplopia Dissociated vertical deviation Esotropia Exotropia Eye care professional ... Primary activities Ocular motility diagnosis & co-management Vision screening. In the UK all school vision screening programmes ...
Convergence is classically spared as cranial nerve III (oculomotor nerve) and its nucleus is spared bilaterally. Causes of the ... There have been cases of improvement in extra-ocular movement with botulinum toxin injection. Internuclear ophthalmoplegia Wall ...
Note, however, that the eye contralateral to the lesion can still move in the direction of the lesion during convergence ... Axial section of the Brainstem (Pons) at the level of the Facial Colliculus Vestibulo-ocular reflex Brain stem sagittal section ... Importantly, despite the lesions, this muscle remains functional during convergence eye movements. Finally, experiments where ...
Ocularists specialize in the fabrication and fitting of ocular prostheses for people who have lost eyes due to trauma or ... convergence and accommodation problems, and conditions such as amblyopia, strabismus, and binocular vision disorders, as ... They do not directly treat ocular disease with medications or surgery. Orthoptists are trained to treat patients using optical ... All three types of professional perform screenings for common ocular problems affecting children (such as amblyopia and ...
Ocular muscles and their disorders. Pioneering the work in their study and treatment. He discovered "Landolt's bodies" between ... OCLC 29693435 On insufficiency of the power of convergence, [S.l. : [s.n.], 1886. OCLC 29693375 The refraction and ... OCLC 83292691 Defective ocular movements and their diagnosis, London, Frowde, 1913. OCLC 14798829 and Marc Landolt Le ... the rods and cones of the outer nuclear layer of the retina, investigated the functions of the ocular muscles and devised a new ...
1] Presumed Ocular Histoplasmosis Syndrome *^ Stefan Dithmar; Frank Gerhard Holz (28 April 2008). Fluorescence Angiography in ... Presumed ocular histoplasmosis syndrome (POHS) is a syndrome affecting the eye, which is characterized by peripheral atrophic ... Thuruthumaly C; Yee D. C.; Rao P. K. (2014). "Presumed ocular histoplasmosis". Current Opinion in Ophthalmology. 25 (6): 508-12 ... Presumed ocular histoplasmosis syndrome and age-related macular degeneration (AMD) have been successfully treated with laser, ...
"Parasympathetic Ocular Control - Functional Subdivisions and Circuitry of the Avian Nucleus of Edinger-Westphal."Science Direct ... in convergence of the eyes and lens adjustment.[20] Nuclei of the optic tract are involved in smooth pursuit eye movement and ... as well as convergence and divergence from photoreceptor to bipolar cell. In addition, other neurons in the retina, ... nerve impulses in the ocular system of the central nervous system. In the presence of light, the retinal molecule changes ...
Having them focus on the object as it is moved in toward their face in the midline will test convergence, or the eyes' ability ... It is known, however, that the vestibulo-ocular reflex plays an important role in the involuntary movement of the eye. Four of ... Dissection showing origins of right ocular muscles, and nerves entering by the superior orbital fissure. View of the orbit from ... the latter is convergence of the two eyes on a near object. Disjunction can be performed voluntarily, but is usually triggered ...
Simultaneously the fellow eye produces a fusional convergence movement as there is no central suppression of that fellow eye. ... ISSN 1040-5488 Pavan-Langston, D. (2008). Manual of ocular diagnosis and therapy. Philadelphia: Wolters Kluwer Health/ ... the fellow eye will not make a fusional convergence movement back in as the image remains in the extended Panum's fusional area ...
There is a measurable ratio between how much convergence takes place because of accommodation (AC/A ratio, CA/C ratio). ... ISBN 978-0-7506-7524-6. oph/723 at eMedicine-"Presbyopia: Cause and Treatment" Ocular+Accommodation at the US National Library ... While it is well understood that proper convergence is necessary to prevent diplopia, the functional role of the pupillary ... The combination of these three movements (accommodation, convergence and miosis) is under the control of the Edinger-Westphal ...
In convergence insufficiency near point of convergence will recede, and positive fusional vergence (PFV) will reduce. So, the ... "Iris and Ciliary body". Current Ocular Therapy (6 ed.). p. 518.CS1 maint: multiple names: authors list (link) Mitchel Scheiman ... Excessive accommodation is seen in association with excessive convergence also. Blurring of vision due to pseudomyopia Headache ... "anomalies of accommodation and convergence". Theory and Practice of Optics and Refraction (2 ed.). Elsevier. pp. 105-106. ...
Convergence-retraction nystagmus: Attempts at upward gaze often produce this phenomenon. On fast up-gaze, the eyes pull in and ... see-saw nystagmus and associated ocular motility deficits including skew deviation, oculomotor nerve palsy, trochlear nerve ... Retraction nystagmus and convergence movement are usually improved with this procedure as well. The eye findings of Parinaud's ... Neuro-Ophthalmic Examination "Convergence-retraction nystagmus". Archived from the original on 14 September 2016. ...
List of systemic diseases with ocular manifestations. References[edit]. *^ a b c Matejcek, A; Goldman, RD (November 2013). " ...
Ocular ischemic syndrome / Central retinal vein occlusion. *Central retinal artery occlusion. *Retinopathy *diabetic ...
Patient remains asymptomatic until epithelial erosions precipitate acute episodes of ocular hyperemia, pain, and photophobia. ...
Martin, G. R.; Ashash, U.; Katzir, Gadi (2001). "Ostrich ocular optics". Brain, Behavior and Evolution. 58 (2): 115-120. doi: ... "Genomic Support for a Moa-Tinamou Clade and Adaptive Morphological Convergence in Flightless Ratites". Molecular Biology and ...
Ocular ischemic syndrome / Central retinal vein occlusion. *Central retinal artery occlusion. *Branch retinal artery occlusion ...
Hodge C, Lawless M (July 2008). "Ocular emergencies". Aust Fam Physician. 37 (7): 506-9. PMID 18592066.. ... Jimmy D. Bartlett; Siret D. Jaanus (2008). Clinical Ocular Pharmacology. Elsevier Health Sciences. pp. 454-. ISBN 978-0-7506- ... they are rarely done because of the cost and the general dearth of laboratory staff experienced in handling ocular specimens. ... "The ocular application of povidone-iodine". Community Eye Health / International Centre for Eye Health. 16 (46): 30-1. PMC ...
Since its cones have a much lesser convergence of signals, the fovea allows for the sharpest vision the eye can attain.[2] ... "Treatment of Leber Congenital Amaurosis Due to RPE65Mutations by Ocular Subretinal Injection of Adeno-Associated Virus Gene ... Since there are about 150 million receptors and only 1 million optic nerve fibres, there must be convergence and thus mixing of ...
Ocular ischemic syndrome / Central retinal vein occlusion. *Central retinal artery occlusion. *Branch retinal artery occlusion ...
Ocular ischemic syndrome / Central retinal vein occlusion. *Central retinal artery occlusion. *Branch retinal artery occlusion ...
Lins, Otavio G.; Picton, Terence W.; Berg, Patrick; Scherg, Michael (1993). "Ocular artifacts in EEG and event-related ... Technological convergence. *Technological evolution. *Technological paradigm. *Technology forecasting *Accelerating change. * ... eye-induced artifacts (includes eye blinks, eye movements and extra-ocular muscle activity) ... this potential regards the eyelids as sliding electrodes that short-circuit the positively charged cornea to the extra-ocular ...
Ocular ischemic syndrome / Central retinal vein occlusion. *Central retinal artery occlusion. *Branch retinal artery occlusion ...
... especially when used to treat ocular tumors. ... Convergence insufficiency. *Internuclear ophthalmoplegia. *One ...
The central mechanisms include the convergence of olfactory nerve axons into glomeruli in the olfactory bulb, where the signal ... Ocular immune system. *Optical coherence tomography. *Eye care professional. *Eye disease. *Refractive error ...
Eye care/screening for children within primary health care is important as catching ocular disease issues can lead to better ...
... previous ocular penetrating trauma or surgery, and other concomitant ocular disease similar to VKH disease.[2][6][11] ... glaucoma and ocular hypertension.[2][3][5][6] Full-blown recurrences are, however, rare after the acute stage is over.[8] ... ocular complications may require an subtenon[6] or intravitreous injection of corticosteroids[4][6] or bevacizumab.[9] In ... Ocular MRI may be helpful[6] and auditory symptoms should undergo audiologic testing.[6] Histopathology findings from eye and ...
Not only is there growth in size and stature (affecting viewing height), but there is also change in inter-ocular distance and ... However, in contrast to simple convergence, the SC integrates information to create an output that differs from the sum of its ... These effects can be ascribed to the convergence of tactile and visual inputs onto neural centers which contain flexible ... "Visual, auditory, and somatosensory convergence on cells in superior colliculus results in multisensory integration". J ...
Imperato, Pascal J. The Convergence of a Virus, Mosquitoes, and Human Travel in Globalizing the Zika Epidemic. (en anglès). ... de Paula Freitas, B; de Oliveira Dias, JR; Prazeres, J; Sacramento, GA; et al «Ocular Findings in Infants With Microcephaly ... Ocular Findings in Infants With Congenital Zika Virus Infection Prakalapakorn, SG. Medscape, WebMD LLC. 2018 Maig 7; pàgs 17 ( ... Guevara JG, Agarwal-Sinha S «Ocular abnormalities in congenital Zika syndrome: a case report, and review of the literature» (en ...
Fraunfelder, Frederick T.; Fraunfelder, Frederick W.; Chambers, Wiley A. (2014). Drug-Induced Ocular Side Effects: Clinical ... Ocular Toxicology E-Book. Elsevier Health Sciences. p. 79. ISBN 978-0-323-31985-0. .. ...
Other experimental presentations may require the use of IPD to control for ocular convergence and binocular depth. ... Hyperstereopsis increases ocular convergence and causes near objects to appear closer and with exaggerated depth and slant. ...
List of systemic diseases with ocular manifestations. References[edit]. *^ Ketring, Kerry I. (2006). "Emergency Treatment for ... This type causes fewer problems than anterior lens luxation, although glaucoma or ocular inflammation may occur. Surgery is ... leading to an obstruction of outflow of aqueous humour and subsequent increase in ocular pressure (glaucoma).[1] Better ...
Berson, E. L.; Rosner, B; Sandberg, M. A.; Weigel-Difranco, C; Dryja, T. P. (1991). "Ocular findings in patients with autosomal ... Berson, Eliot L.; Rosner, B; Sandberg, M. A.; Dryja, T. P. (1991). "Ocular Findings in Patients with Autosomal Dominant ...
Ocular ischemic syndrome/Central retinal vein occlusion. * رتینوپاتی * Bietti's crystalline dystrophy. * Coats disease ...
Ocular ischemic syndrome / Central retinal vein occlusion. *Central retinal artery occlusion. *Retinopathy *diabetic ...
Phakic intra-ocular lens[edit]. Instead of modifying the corneal surface, as in laser vision correction (LVC), this procedure ... Index myopia is attributed to variation in the index of refraction of one or more of the ocular media.[50] Cataracts may lead ... Ledford, Al Lens, Sheila Coyne Nemeth, Janice K. (2008). Ocular anatomy and physiology (2nd ed.). Thorofare, NJ: SLACK. p. 158 ... Index myopia is attributed to variation in the index of refraction of one or more of the ocular media.[50] ...
Divergence and convergence: In the human cerebellum, information from 200 million mossy fiber inputs is expanded to 40 billion ... Studies of the vestibulo-ocular reflex (which stabilizes the visual image on the retina when the head turns) found that ...
Hobson, David W. (1991). Dermal and Ocular Toxicology: Fundamentals and Methods. CRC Press. p. 485. ISBN 0-8493-8811-2.. ...
Ocular straylight. References[edit]. *^ a b Cline D; Hofstetter HW; Griffin JR. Dictionary of Visual Science. 4th ed. ... They also carry a high risk of damage to surrounding ocular tissue. Accordingly, vitreolysis is not widely practised, being ...
... similar to that seen in ocular ischemic syndrome. Since the central retinal artery and vein are the sole source of blood supply ...
Ocular torticollis refers to a head tilt that is caused by an ocular misalignment. Opsoclonus refers to rapid, conjugate ... Ocular Motility Disorders: Disorders that feature impairment of eye movements as a primary manifestation of disease. These ... Convergence; Internuclear Ophthalmoplegias; Ocular Dyskinesia, Paroxysmal; Ocular Dyskinesias, Paroxysmal; Ocular Motility ... Ocular Motility Disorders (Convergence Insufficiency). Subscribe to New Research on Ocular Motility Disorders ...
Ocular Accommodation, Convergence, and Fixation Disparity A Manual of Clinical Analysis. Ocular Accommodation, Convergence, and ... Goss, David A. is the author of Ocular Accommodation, Convergence, and Fixation Disparity A Manual of Clinical Analysis with ...
Definition of Unit of ocular convergence with photos and pictures, translations, sample usage, and additional links for more ... Unit Of Ocular Convergence Images Lexicographical Neighbors of Unit Of Ocular Convergence. unit matrix. unit matrixes. unit ... Medical Definition of Unit of ocular convergence. 1. The amount of convergence required to view binocularly an object 1 meter ... unit of ocular convergence (current term). unit of oxytocin. unit of penicillin. unit of radioactivity. unit of thyrotrophic ...
... Eur Rev Med Pharmacol Sci Year: 2017. Vol. 21 - N. 5 Pages: 1088-1090 ... Psychogenic convergence spasm mimicking ocular myasthenia. C. Scoppetta, G. Di Gennaro. Department of Human Physiology and ... She has been previously diagnosed by experienced neurologists as having ocular myasthenia and she had been treated for two ... After a thorough medical interview and neurological examination, a diagnosis of psychogenic convergence spasm was made. The ...
Development and characterization of biomaterials for a wide variety of anterior ocular applications. ...
Individuals with schizophrenia (SZ) have been reported to exhibit a higher prevalence of convergence insufficiency (CI) than ... purpose of this study was to determine if individuals with SZ exhibit clinical signs of CI and to determine if the Convergence ...
Corneal and External Ocular Disease*Diabetic Retinopathy*Eye Laser*Glaucoma*Neuro-Ophthalmology*Ocular Oncology and Eye Tumors* ... Ocular Oncology and Eye Tumors*Inherited Retinal Diseases and Degenerations / Retinitis Pigmentosa*Uveitis and Ocular ... Simple, Low-Cost Smartphone Adapter for Rapid, High Quality Ocular Anterior Segment Imaging: A Photo Diary, Journal of Mobile ... Ophthalmology Department hosting second annual Ocular Melanoma Benefit 5K Fun Run and Walk*Precision Medicine Will Rely on ...
ocular motility conditions. *accommodative dysfunction. *asthenopia. *convergence insufficiency. *visual field deficits ... One study found that eye exercises can help with convergence problems. Another study suggested that eye exercises improved ... Pencil pushups can help people with convergence insufficiency. A doctor might recommend this exercise as part of vision therapy ... The pencil pushups exercise appears to be an effective therapy for symptomatic convergence insufficiency. ...
Ocular Motility Disorders. Central Nervous System Diseases. Nervous System Diseases. Cranial Nerve Diseases. Eye Diseases. ... Randomized Trial of Treatments for Convergence Insufficiency. The safety and scientific validity of this study is the ... Convergence Insufficiency Procedure: Pencil Push-ups Procedure: Office-based Vision Therapy Procedure: Placebo Office-based ... Any ocular or systemic medication known to affect accommodation or vergence. *Monocular accommodative amplitude less than 4 D ...
Ocular Motility Disorders. Central Nervous System Diseases. Nervous System Diseases. Cranial Nerve Diseases. Eye Diseases. ... Convergence Insufficiency Other: Active home-based computer vergence/accommodative therapy Procedure: Near target push-ups ... Near point of convergence (NPC) break: 12-week/baseline mean NPC break ,0.763 and a mean 12-week NPC break ,6 cm ... Near point of convergence (NPC) break: 12-week/baseline mean NPC break ,0.763 and a mean 12-week NPC break ,6 cm ...
Patients with previous ocular or strabismus surgery. *Patients with ocular or neurologic pathologic conditions ... Early Results of Slanted Recession of the Lateral Rectus Muscle for Intermittent Exotropia With Convergence Weakness. The ... Early Results of Slanted Recession of the Lateral Rectus Muscle for Intermittent Exotropia With Convergence Weakness; A ... All patients who had intermittent exotropia with convergence weakness was enrolled to the slanted lateral rectus muscle ...
... that asthenopia is a consequence of anomalous oculomotor responses generated by conflict between accommodative and convergence ... Accommodation, Ocular* * Adult * Asthenopia / physiopathology* * Asthenopia / psychology * Convergence, Ocular* * Depth ... Target spatial frequency determines the response to conflicting defocus- and convergence-driven accommodative stimuli Vision ... Under the low-conflict conditions accommodation was stable, but convergence-driven accommodation was dominant when the target ...
Ocular Accommodation. Convergence, Excess. Interventions Device: Test Daily Disposable Soft Contact Lenses. Device: Control ... Convergence Insufficiency Symptom Survey (CISS) Description Difference in CISS score after one week of multifocal Description ... Rouse MW, Borsting EJ, Mitchell GL, Scheiman M, Cotter SA, Cooper J, Kulp MT, London R, Wensveen J; Convergence Insufficiency ... Validity and reliability of the revised convergence insufficiency symptom survey in adults. Ophthalmic Physiol Opt. 2004 Sep;24 ...
Convergence, Ocular* * Female * Humans * Male * Postural Balance* * Strabismus / physiopathology * Strabismus / psychology * ...
Ocular Convergence Spasm. *Ocular Histoplasmosis Syndrome. *Ocular Hypertension. *Ocular Inflammation (Uveitis) Treatment ...
Ocular Convergence Spasm. *Pediatric Eye and Vision Examination. *Poor Ocular Motion. *Post-Concussion Syndrome ...
Accommodation, Accommodative insufficiency, Binocular vision, Convergence, Convergence insufficiency, Fatigue, Myasthenia ... Accommodative and Vergence Findings in Ocular Myasthenia: PDF Only. Cooper Jeffrey MS OD; Pollak, Gayle J. OD; Ciuffreda, ... Accommodative and Vergence Findings in Ocular Myasthenia: A Case Analysis Journal of Neuro-Ophthalmology20(1):5-11, March 2000 ... Validity of Forced Eyelid Closure Test: A Novel Clinical Screening Test for Ocular Myasthenia Gravis ...
Ocular Dominance Determined by Near Point of Convergence Test in Intermittent Exotropia ... Ocular Dominance Determined by Near Point of Convergence Test in Intermittent Exotropia ... This study was designed to validate the usefulness of the near point of convergence(NPC)test in determination of dominant & non ... Ocular Language: Korean Journal: Journal of the Korean Ophthalmological Society Year: 2000 Type: Article ...
abduction action amblyopia ametropia angle kappa angle of convergence annulus of Zinn asthenopia astigmatism attachment ... The Extra-ocular Muscles; a Clinical Study of Normal and Abnormal Ocular Motility. The Extra-ocular Muscles; a Clinical Study ... The Extra-ocular Muscles; a Clinical Study of Normal and Abnormal Ocular Motility. ... gb-gplus-shareThe Extra-ocular Muscles; a Clinical Study of Normal and Abnormal Ocular Motility. ...
There is typically an exophoria or intermittent exotropia at near, a receded near point of convergence, reduced positive ... Convergence insufficiency is a common condition that is characterized by a patient s inability to maintain proper binocular ... Binocular Vision & Ocular Motility: Theory & Management of Strabismus. 5th ed. Mosby-Year Book; 1995. 468-476. ... encoded search term (Convergence Insufficiency) and Convergence Insufficiency What to Read Next on Medscape. Related Conditions ...
Hawthorne, F. Convergence of Genetic Disease Association and Ocular Expression. DUKE University library, 1-198 (2012). ... He, S., Li, X., Chan, N. & Hinton, D. R. Review: Epigenetic mechanisms in ocular disease. Mol Vis 19, 665-674 (2013). ... One of the drawbacks of the study is that this analysis used blood DNA and not ocular tissue DNA. Nevertheless, this study ... Nine loci for ocular axial length identified through genome-wide association studies, including shared loci with refractive ...
Ocular Alignment. *Visual Fixation. *Light Touch. *Saccadic Eye Movement. *Convergence. *Visual Spatial Inattention ...
Vestibular and Ocular Function. The Vestibular/Ocular Motor Screen (VOMS) was utilized to measure vestibular and ocular ... The subtests include smooth pursuits, horizontal and vertical saccades, near-point of convergence (NPC), horizontal and ... A brief Vestibular/Ocular Motor Screening (VOMS) assessment to evaluate concussions: preliminary findings. Am J Sports Med. ... A brief Vestibular/Ocular Motor Screening (VOMS) assessment to evaluate concussions: preliminary findings. Am J Sports Med. ...
... consisting of the Vestibular/Ocular Motor Screening (VOMS), near point of convergence (NPC), and the King-Devick (K-D) tests. ... Mucha ACollins MWElbin RJFurman JMTroutman-Enseki CDeWolf RM: A brief Vestibular/Ocular Motor Screening (VOMS) assessment to ... Kontos APSufrinko AElbin RJPuskar ACollins MW: Reliability and associated risk factors for performance on the Vestibular/Ocular ... Moran RNCovassin TElbin RJGould DNogle S: Reliability and normative reference values for the Vestibular/Ocular Motor Screening ...
Le, T. T., and Kapoula, Z. (2008). Role of ocular convergence in the Romberg quotient. Gait Posture 27, 493-500. doi: 10.1016/j ... Matheron, E., Yang, Q., Le, T. T., and Kapoula, Z. (2008). Effects of ocular dominance on the vertical vergence induced by a 2- ... As explained in Section "Materials and Methods," the eye movements involved convergence and divergence eye movements, which ...
Researchers used a medical record retrieval system to describe the clinical characteristics of convergence insufficiency (CI) ... Convergence insufficiency (CI) is a common disorder of ocular alignment among both children and adults. It is characterized by ... "Convergence insufficiency is one of few forms of ocular misalignment that is relatively common in both children and adults. ... CI is diagnosed on the findings of a remote near point of convergence and decreased fusional convergence at near fixation. ...
The convergence near-point test. The subject fixates an object that is moved toward the nose until divergence of one eye occurs ... Ocular dominance, sometimes called eye preference or eyedness, is the tendency to prefer visual input from one eye to the other ... Ocular dominance column Right- and left-hand traffic Chaurasia BD, Mathur BB (1976). "Eyedness". Acta Anatomica. 96 (2): 301-5 ... Handa T, Mukuno K, Uozato H, Niida T, Shoji N, Minei R, Nitta M, Shimizu K (April 2004). "Ocular dominance and patient ...
Normalize associated deficiencies in ocular motor control and accommodation. *Normalize accommodative/convergence relationship ... Idiopathic convergence insufficiency responds very well to convergence exercises and has a very high reported success rate. ... Convergence Insufficiency Treatment Trial Study Group. Randomized clinical trial of treatments for symptomatic convergence ... Convergence Insufficiency Treatment Trial Study Group. Randomized clinical trial of treatments for symptomatic convergence ...
Impaired convergence. 0000619 Impaired ocular abduction. 0000634 Impaired ocular adduction. 0000542 Palpebral fissure narrowing ... Differential diagnosis includes Duane-radial ray syndrome, acro-renal-ocular syndrome, Bosley-Salih-Alorainy syndrome, Townes- ...
It consists of performing visual exercises to improve certain eye defects; improve ocular convergence and divergence; and ... Through orthoptics, visual exercises are performed that improve some eye defects, improve convergence, ocular divergence and ...
  • Ocular torticollis refers to a head tilt that is caused by an ocular misalignment. (
  • Convergence insufficiency is one of few forms of ocular misalignment that is relatively common in both children and adults. (
  • A form of ocular misalignment where the visual axes diverge inappropriately. (
  • Prolonged Constant Eye Misalignment Leads to failure to Develop Binocular Vision in Childhood Ocular Myasthenia Gravis. (
  • Purpose: Variable eye misalignment and blepharoptosis in childhood ocular myasthenia gravis can lead to permanent binocular visual loss. (
  • Khawam E, Abiad B, Boughannam A, Saade J, Alameddine R. Convergence Insufficiency/Divergence Insufficiency Convergence Excess/Divergence Excess: Some Facts and Fictions. (
  • Through orthoptics, visual exercises are performed that improve some eye defects, improve convergence, ocular divergence and stimulate or relax the system that focuses and moves the eyes. (
  • 0.03).A weaker correlation was observed for the near convergence steps (r = 0.59, p = 0.20).Future investigations should include a systematic study of how prisms may influence convergence and divergence eye movements for those prescribed with prisms within their spectacles. (
  • Future investigations should include a systematic study of how prisms may influence convergence and divergence eye movements for those prescribed with prisms within their spectacles. (
  • In addition to these pathways, over which impulses originating in the cochlea reach the cerebral cortex, there are corticofugal connections and interneuronal circuits that, together with ascending projections, provide numerous opportunities at all levels of the auditory system for convergence and divergence of afferent input, serial and parallel processing of information, and feedback modulation. (
  • In contrast, the steps between microscopic sensory inputs and microscopic motor outputs require wide divergence and convergence of axonal and dendritic connections to encompass very many neurons. (
  • Each level has the statistical properties of divergence and convergence though with differing emphases. (
  • Adaptive plasticity in the naso-occipital linear vestibulo-ocular reflex. (
  • Canal-otolith interactions in the squirrel monkey vestibulo-ocular reflex and the influence of fixation distance. (
  • Influence of sensorimotor context on the linear vestibulo-ocular reflex. (
  • In a simple clinical classification they can be separated according to the three major planes of action of the vestibulo-ocular reflex: yaw, roll, and pitch. (
  • One of the best-studied examples is that of visuo-vestibular interaction, which is the ability of the visual system to enhance or suppress the vestibulo-ocular reflex (VOR suppression). (
  • Other ocular disorders included age-related macular degeneration in 17 percent and glaucoma in 8 percent of patients. (
  • 3. Amano Y, Sugimoto Y, Sugita M. Ocular disorders due to eyelash extensions. (
  • In this study, we assessed saccadic reading using variations of the King-Devick (KD) test, a rapid single digit number naming test, as a way to assess the ability to make serial left-to-right ocular motor movements necessary for reading. (
  • After a thorough medical interview and neurological examination, a diagnosis of psychogenic convergence spasm was made. (
  • The examination includes determining the distance from the eyes that the patient can hold the eyes together without double vision (near point of convergence) and the amount of prism that can be placed in front of the eyes at a particular distance before double vision is seen (fusional vergence amplitude). (
  • During a routine eye examination, convergence weakness may be diagnosed even without the above-mentioned symptoms. (
  • Patient's ocular examination shows yellow reflex and exotropia. (
  • Between-groups comparisons were performed for vestibular symptoms and provocation scores on the VOMS (smooth pursuit, saccades, convergence, vestibular/ocular reflex, visual motion sensitivity), NPC (average distance), and K-D (time). (
  • Understanding the neuroanatomical substrates involved in vergence aids in understanding how these pathways are affected by disease and how they interact with other ocular motor networks such as saccades. (
  • Functional vision refers to a variety of specific functions of the eye and the neurological control of these functions such as binocularity , pursuit, saccades, accommodation, convergence etc., while perceptual vision refers to understanding, identifying and judging the importance of what you see. (
  • We discuss the ocular findings, including those from optical coherence tomography, in JS, which has recently been recognized as ciliopathy. (
  • Furthermore, there have been no cases examined by optical coherence tomography (OCT). Herein, we describe ocular findings in two siblings with JS. (
  • Individuals diagnosed with migraine headaches reported greater VOMS smooth pursuit scores (p = 0.02), convergence scores (p = 0.04), vestibular ocular reflex scores (p value range 0.002-0.04), and visual motion sensitivity scores (p = 0.009). (
  • It has been proposed that asthenopia is a consequence of anomalous oculomotor responses generated by conflict between accommodative and convergence stimuli. (
  • Convergence insufficiency (CI) is a common disorder of ocular alignment among both children and adults. (
  • IN can appear as an isolated ocular motor abnormality with nearly normal acuity or in association with a visual sensory disorder including opacities of the ocular media (cornea, lens, or vitreous) and functional abnormalities of the macula (albinism and aniridia) or optic nerve. (
  • Introduction: Convergence insufficiency (CI) is a common binocular disorder in which the eyes do not work at near easily. (
  • Conclusion: Convergence insufficiency disorder frequently goes undetected in school age children. (
  • Simmons, D. and Toal, E. (2012) Autism, attention-deficit/heyperactivity disorder, and ocular disease. (
  • The projects are ambitious and wide-ranging: ocular portraits of Post-Traumatic Stress Disorder sufferers, visualizations of noise in the brain, stereoscopes that reveal brain arousal, and memes that explore the benefits of drinking water before bed. (
  • Infantile nystagmus (IN) refers to involuntary ocular oscillations that begin during the first 6 months of life. (
  • Nystagmus amplitude typically increases with visual effort and dampens with convergence and sleep. (
  • If the reason of nystagmus is of ocular origin, we have to treat the underlying disease. (
  • A tonic imbalance in roll is defined by torsional nystagmus, skew deviation, ocular torsion, tilts of head, body, and the perceived vertical. (
  • The most common is associated with vertical ocular nystagmus with the lid movement being synchronous with the eyes, but with greater aplitutde. (
  • A patient with the third type, convergence evoked lid nystagmus, which is usually associated with a lesion in the medial medulla, is shown. (
  • Rouse MW, Hyman L, Hussein M, Solan H. Frequency of convergence insufficiency in optometry clinic settings. (
  • The Convergence Insufficiency Treatment Trial (CITT) is a prospective, masked-examiner, multi-center clinical trial in which patients are randomized to one of these two treatment approaches. (
  • This prospective study included 31 patients who underwent slanted lateral rectus muscle recession for intermittent exotropia with convergence weakness. (
  • All patients who had intermittent exotropia with convergence weakness was enrolled to the slanted lateral rectus muscle recession group. (
  • Only patients in the vision therapy/orthoptics group demonstrated statistically and clinically significant changes in the near point of convergence (12.8 cm to 5.3 cm, p = 0.002) and positive fusional vergence at near (11.3Delta to 29.7Delta, p = 0.001). (
  • This study was designed to validate the usefulness of the near point of convergence(NPC)test in determination of dominant & non-domnant eyes in intermittent exotropia patients . (
  • Cohen M, Groswasser Z, Barchadski R, Appel A. Convergence insufficiency in brain-injured patients. (
  • Although home-based convergence exercises are the most commonly prescribed treatment, three of four patients in this study were managed with prism correction and only 9 percent with convergence exercises. (
  • To evaluate refractive, binocular vision and ocular alignment outcomes of photorefractive keratectomy (PRK) for the treatment of hyperopia in esotropic patients. (
  • Roberts, D. Ocular Characteristics of Patients with Optic Nerve Hypoplasia. (
  • Results: After the treatment of the convergence insufficiency by orthoptic procedures, between the great numbers of patients above symptoms were reduced or disappeared. (
  • Convergence insufficiency can be successfully managed and it will allow these patients more comfortable and better quality of life. (
  • This article aims to report two atypical cases of ocular sporotrichosis in immunocompetent patients, both presenting a clinical picture compatible with Parinaud oculoglandular syndrome associated with dacryocystitis in one case and presumably to choroiditis in the other case. (
  • The presence of convergence insufficiency did not significantly correlate with reading time in PD patients, although on average there was slower reading time in those with convergence insufficiency by 8 s (p = 0.2613). (
  • Reversible, nonlimiting neuromuscular toxicity evidenced as diplopia because of pareses of the external ocular muscles was present in 13 patients. (
  • Vision training has been found to be successful in improving stereovision, giving patients the ability to see in 3D, and for convergence insufficiency. (
  • Convergence Insufficiency Treatment Trial (CITT) Study Group. (
  • The convergence insufficiency treatment trial: design, methods, and baseline data. (
  • The purpose of this study is to determine the effectiveness of home-based computer therapy for symptomatic convergence insufficiency (CI) compared to traditional home-based near target push-ups and placebo treatment. (
  • The purpose of this article is to compare vision therapy/orthoptics, pencil pushups, and placebo vision therapy/orthoptics as treatments for symptomatic convergence insufficiency in adults 19 to 30 years of age. (
  • In a randomized, multicenter clinical trial, 46 adults 19 to 30 years of age with symptomatic convergence insufficiency were randomly assigned to receive 12 weeks of office-based vision therapy/orthoptics, office-based placebo vision therapy/orthoptics, or home-based pencil pushups. (
  • Goss, David A. is the author of 'Ocular Accommodation, Convergence, and Fixation Disparity A Manual of Clinical Analysis' with ISBN 9780409903065 and ISBN 040990306X. (
  • CI is diagnosed on the findings of a remote near point of convergence and decreased fusional convergence at near fixation. (
  • Influence of age, spatial memory, and ocular fixation on localization of auditory, visual, and bimodal targets by human subjects. (
  • Sustained fixation induced changes in phoria and convergence peak velocity. (
  • As a result of sustained fixation, phoria was adapted and the peak velocity of the near and far convergence steps was modified. (
  • Most of the nuclear structures and pathways concerned with fixation and stable ocular movements are now known and much has been learned of their physiology both from clinical-pathologic correlations in humans and from experiments in monkeys. (
  • The child's ocular motor balance (with and without habitual correction) should be evaluated with both distance and near fixation if possible. (
  • The primary outcome was to assess the efficacy of PRK in improving ocular alignment. (
  • I suspect that your distance vision after Lasik may be fine and not subject to headaches, but that mid-distance and near vision will cause you problems due to the alignment and convergence issues. (
  • An ocular alignment system for aligning a subject's eye with an optical axis of an ocular imaging device comprising one or more guide light and one or more. (
  • The child's ocular health should be examined for signs of pathology and neurological deficits. (
  • This classification will be based on the level of improvement in both the signs (near point of convergence and positive fusional vergence) and symptoms of CI. (
  • Are there differences in the distributions of changes in near point of convergence, positive fusional vergence, or accommodative amplitudes, between the two treatment groups, at twelve weeks and at one-year of follow up? (
  • Secondary outcome measures were the near point of convergence and positive fusional vergence at near. (
  • In this study, vision therapy/orthoptics was the only treatment that produced clinically significant improvements in the near point of convergence and positive fusional vergence. (
  • Loss of fusional vergence with partial loss of accommodative convergence and accommodation following head injury. (
  • Thus, the vergence system is an important component of ocular motor control and is essential for achieving a coherent visual image. (
  • The generation of vergence commands starts with premotor commands, which are generated in the brainstem and then transmitted via ocular motor neurons to the extraocular muscles. (
  • This study sought to investigate the influence of phoria adaptation on convergence peak velocity from responses located at different initial vergence positions. (
  • Two different sustained fixations (1° and 16° convergent rotation along the subject's midline) were used to study whether phoria had an influence on the peak velocity of convergence responses located at two initial vergence positions (1° or 'far' steps and 12° or 'near' steps). (
  • The incidence and clinical characteristics of adult-onset convergence insufficiency. (
  • Relationship between clinical signs and symptoms of convergence insufficiency. (
  • We propose that a simple reading task using 120 single-digit numbers can be used as a screening tool in the clinical setting to assess functional ocular motor difficulties in Parkinson's disease that can have a profound impact on quality of life. (
  • She has been previously diagnosed by experienced neurologists as having ocular myasthenia and she had been treated for two years with anticholinesterase inhibitors and immunomodulatory drugs. (
  • Orthoptics training refers to techniques designed to correct accommodative and convergence insufficiency (or convergence dysfunction). (
  • The management of the symptoms and signs caused by paradoxical conjugated ocular movements is difficult. (
  • The child's visual and medical history, ensuring that previous ocular treatment is noted as well as whether the child has any particular developmental or medical history. (
  • Subjects viewed a high contrast Maltese Cross target at three levels of Gaussian filter target blur under conditions of relatively low- and high-conflict between accommodation and convergence stimuli, the latter inducing the sensation of stereopsis. (
  • If indicated, a hysterectomy relative to one's internal states, because internal cues are ocular convergence and stereopsis. (
  • One might say that the ocular muscles are at the service of vision. (
  • Accurate binocular vision is actually achieved by the associated action of all the ocular muscles. (
  • Each patient's entire medical record was reviewed for other ocular or medical conditions. (
  • Convergence insufficiency is diagnosed by an ophthalmologist, optometrist or orthoptist after obtaining a history of the patient's symptoms and measuring convergence ability. (
  • Abnormalities of ocular movement are of three basic types. (
  • Ocular and oculomotor abnormalities are common in JS and are helpful in making a diagnosis. (
  • The point closest to the eyes at which the monocular fields overlap is termed the binocular convergence point, and the distance from this point to the central point midline of the head is the convergence distance. (
  • The extent of binocular convergence in response to a near target should be assessed. (
  • these same forces can affect the eyes, orbital tissues, and ocular adnexa. (
  • Their second major discovery was a further organizationof the cortical cells into roughly vertical divisions of two types: orientation columns and ocular dominance columns. (
  • The formation of ocular dominance columns is an exemplar. (
  • One study found that eye exercises can help with convergence problems. (
  • A personalized action plan was designed to minimize suppression and to improve left-right ocular motor symmetry, which included home exercises and structured vision training. (
  • 1. The amount of convergence required to view binocularly an object 1 meter distant and exerting 1 diopter of accommodation. (
  • The hypothesis was examined by measuring accommodation and convergence continuously with a Shin-Nippon SRW5000 infrared autorefractor and a limbus tracking device. (
  • Under the low-conflict conditions accommodation was stable, but convergence-driven accommodation was dominant when the target was extremely blurred. (
  • Under the high-conflict conditions the role of convergence-driven accommodation increased systematically with the degree of target blur. (
  • Ohtsuka K, Maeda S, Oguri N. Accommodation and convergence palsy caused by lesions in the bilateral rostral superior colliculus. (
  • It is shown that trained observers change their level of accommodation, when viewing a target at a constant distance, to compensate for the varying ocular longitudinal chromatic aberration as the color of the target is changed. (
  • Dynamic aspects of these effects are illustrated and it is shown that the ocular longitudinal chromatic aberration increases slightly with accommodation. (
  • To evaluate the changes in the stimulus and response Accommodative Convergence to Accommodation (AC/A) ratio following vision therapy (VT) in Convergence Insufficiency (CI). (
  • 4 5 6 7 8 Jacobs and Dell'Osso 9 have recently proposed a defect in smooth pursuit and gaze-holding ocular motor systems. (
  • Symptoms of convergence insufficiency include diplopia (double vision), eyestrain, eye fatique, tension in and around the eyes, headaches when reading, and squinting or closing of one eye. (
  • Convergence insufficiency in idiopathic Parkinson's disease responsive to levodopa. (
  • Ocular Surface Disease and Convergence Insufficiency: Overlap of Symptoms. (
  • It is a condition in which the best corrected vision in one eye is poorer than 20/20 (6/6) in the absence of any obvious structural anomalies or ocular disease. (
  • Horwood AM, Toor S, Riddell PM. Screening for convergence insufficiency using the CISS is not indicated in young adults. (
  • Outcomes were recovery time, Postconcussion Symptom Scale (PCSS), Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), Vestibular/Ocular Motor Screen (VOMS), and demographics, medical history, and injury information. (
  • Six of the 12 cranial nerves pertain to vision and visual/ocular functions. (
  • Not all symptoms are present in every patient with convergence weakness. (
  • Among this age group, ocular causes for headache like uncorrected refractory errors like various types of astigmatism as well as hypermetropia with asthenopic symptoms were present. (
  • The signs and symptoms of this condition are exactly the same as convergence insufficiency. (
  • This distinction, in keeping with the general concept of upper and lower motor neuron paralysis, hardly portrays the complexity of the neural mechanisms governing ocular motility. (
  • ABSTRACT The disturbances in ocular motility are the cause of periodical consultation in Ophthalmology. (
  • Ocular dominance, sometimes called eye preference or eyedness, is the tendency to prefer visual input from one eye to the other. (
  • They termed the process of puttingthe millions of building blocks of visual information back together into a picture "convergence. (
  • Visual performance can be impaired through damage to cortical, brainstem, cranial nerve, or ocular structures. (
  • Dieterich M, Brandt T (1993) Ocular torsion and tilt of subjective visual vertical are sensitive brainstem signs. (
  • A-B ) Visual stimulus-aligned ( A ) and eye convergence-aligned ( B ) ΔF/F 0 responses for all 36 clusters. (
  • This article provides an overview of the most important and frequent forms of central vestibular vertigo syndromes, including basilar/vestibular migraine, which are characterized by ocular motor, postural, and perceptual signs. (