Scotoma: A localized defect in the visual field bordered by an area of normal vision. This occurs with a variety of EYE DISEASES (e.g., RETINAL DISEASES and GLAUCOMA); OPTIC NERVE DISEASES, and other conditions.Visual Field Tests: Method of measuring and mapping the scope of vision, from central to peripheral of each eye.Visual Fields: The total area or space visible in a person's peripheral vision with the eye looking straightforward.Perceptual Closure: The tendency to perceive an incomplete pattern or object as complete or whole. This includes the Gestalt Law of Closure.Ophthalmoscopy: Examination of the interior of the eye with an ophthalmoscope.Retinal DiseasesOphthalmoscopes: Devices for examining the interior of the eye, permitting the clear visualization of the structures of the eye at any depth. (UMDNS, 1999)Fixation, Ocular: The positioning and accommodation of eyes that allows the image to be brought into place on the FOVEA CENTRALIS of each eye.Macula Lutea: An oval area in the retina, 3 to 5 mm in diameter, usually located temporal to the posterior pole of the eye and slightly below the level of the optic disk. It is characterized by the presence of a yellow pigment diffusely permeating the inner layers, contains the fovea centralis in its center, and provides the best phototropic visual acuity. It is devoid of retinal blood vessels, except in its periphery, and receives nourishment from the choriocapillaris of the choroid. (From Cline et al., Dictionary of Visual Science, 4th ed)ReadingVisual Acuity: 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.Hemianopsia: Partial or complete loss of vision in one half of the visual field(s) of one or both eyes. Subtypes include altitudinal hemianopsia, characterized by a visual defect above or below the horizontal meridian of the visual field. Homonymous hemianopsia refers to a visual defect that affects both eyes equally, and occurs either to the left or right of the midline of the visual field. Binasal hemianopsia consists of loss of vision in the nasal hemifields of both eyes. Bitemporal hemianopsia is the bilateral loss of vision in the temporal fields. Quadrantanopsia refers to loss of vision in one quarter of the visual field in one or both eyes.Macular Degeneration: Degenerative changes in the RETINA usually of older adults which results in a loss of vision in the center of the visual field (the MACULA LUTEA) because of damage to the retina. It occurs in dry and wet forms.Vision, Low: Vision considered to be inferior to normal vision as represented by accepted standards of acuity, field of vision, or motility. Low vision generally refers to visual disorders that are caused by diseases that cannot be corrected by refraction (e.g., MACULAR DEGENERATION; RETINITIS PIGMENTOSA; DIABETIC RETINOPATHY, etc.).Telescopes: Instruments used to observe distant objects.Fovea Centralis: An area approximately 1.5 millimeters in diameter within the macula lutea where the retina thins out greatly because of the oblique shifting of all layers except the pigment epithelium layer. It includes the sloping walls of the fovea (clivus) and contains a few rods in its periphery. In its center (foveola) are the cones most adapted to yield high visual acuity, each cone being connected to only one ganglion cell. (Cline et al., Dictionary of Visual Science, 4th ed)Night Vision: Function of the human eye that is used in dim illumination (scotopic intensities) or at nighttime. Scotopic vision is performed by RETINAL ROD PHOTORECEPTORS with high sensitivity to light and peak absorption wavelength at 507 nm near the blue end of the spectrum.Afterimage: Continuation of visual impression after cessation of stimuli causing the original image.Nystagmus, Optokinetic: Normal nystagmus produced by looking at objects moving across the field of vision.Fundus Oculi: 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)Eye Movements: Voluntary or reflex-controlled movements of the eye.Fluorescein Angiography: 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.Vision Tests: A series of tests used to assess various functions of the eyes.Sensory Aids: Devices that help people with impaired sensory responses.PubMed: A bibliographic database that includes MEDLINE as its primary subset. It is produced by the National Center for Biotechnology Information (NCBI), part of the NATIONAL LIBRARY OF MEDICINE. PubMed, which is searchable through NLM's Web site, also includes access to additional citations to selected life sciences journals not in MEDLINE, and links to other resources such as the full-text of articles at participating publishers' Web sites, NCBI's molecular biology databases, and PubMed Central.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.Prefrontal Cortex: The rostral part of the frontal lobe, bounded by the inferior precentral fissure in humans, which receives projection fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from numerous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical afferents of visual, auditory, and somatic origin.BooksPublishing: "The business or profession of the commercial production and issuance of literature" (Webster's 3d). It includes the publisher, publication processes, editing and editors. Production may be by conventional printing methods or by electronic publishing.MEDLINE: The premier bibliographic database of the NATIONAL LIBRARY OF MEDICINE. MEDLINE® (MEDLARS Online) is the primary subset of PUBMED and can be searched on NLM's Web site in PubMed or the NLM Gateway. MEDLINE references are indexed with MEDICAL SUBJECT HEADINGS (MeSH).Optic Chiasm: The X-shaped structure formed by the meeting of the two optic nerves. At the optic chiasm the fibers from the medial part of each retina cross to project to the other side of the brain while the lateral retinal fibers continue on the same side. As a result each half of the brain receives information about the contralateral visual field from both eyes.Optic Neuritis: Inflammation of the optic nerve. Commonly associated conditions include autoimmune disorders such as MULTIPLE SCLEROSIS, infections, and granulomatous diseases. Clinical features include retro-orbital pain that is aggravated by eye movement, loss of color vision, and contrast sensitivity that may progress to severe visual loss, an afferent pupillary defect (Marcus-Gunn pupil), and in some instances optic disc hyperemia and swelling. Inflammation may occur in the portion of the nerve within the globe (neuropapillitis or anterior optic neuritis) or the portion behind the globe (retrobulbar neuritis or posterior optic neuritis).Optic Nerve: The 2nd cranial nerve which conveys visual information from the RETINA to the brain. The nerve carries the axons of the RETINAL GANGLION CELLS which sort at the OPTIC CHIASM and continue via the OPTIC TRACTS to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the SUPERIOR COLLICULI and the SUPRACHIASMATIC NUCLEI. Though known as the second cranial nerve, it is considered part of the CENTRAL NERVOUS SYSTEM.Optic Disk: 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.Eye: 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.Retinal Neurons: Nerve cells of the RETINA in the pathway of transmitting light signals to the CENTRAL NERVOUS SYSTEM. They include the outer layer of PHOTORECEPTOR CELLS, the intermediate layer of RETINAL BIPOLAR CELLS and AMACRINE CELLS, and the internal layer of RETINAL GANGLION CELLS.Visual Perception: The selecting and organizing of visual stimuli based on the individual's past experience.Optic Atrophy: Atrophy of the optic disk which may be congenital or acquired. This condition indicates a deficiency in the number of nerve fibers which arise in the RETINA and converge to form the OPTIC DISK; OPTIC NERVE; OPTIC CHIASM; and optic tracts. GLAUCOMA; ISCHEMIA; inflammation, a chronic elevation of intracranial pressure, toxins, optic nerve compression, and inherited conditions (see OPTIC ATROPHIES, HEREDITARY) are relatively common causes of this condition.Optic Atrophy, Autosomal Dominant: Dominant optic atrophy is a hereditary optic neuropathy causing decreased visual acuity, color vision deficits, a centrocecal scotoma, and optic nerve pallor (Hum. Genet. 1998; 102: 79-86). Mutations leading to this condition have been mapped to the OPA1 gene at chromosome 3q28-q29. OPA1 codes for a dynamin-related GTPase that localizes to mitochondria.Retina: 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.Visual Cortex: Area of the OCCIPITAL LOBE concerned with the processing of visual information relayed via VISUAL PATHWAYS.Photic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Learning: Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Anatomy: A branch of biology dealing with the structure of organisms.Visual Pathways: 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.
  • These findings suggest a need for a reconsideration of the concept of the mnemonic scotoma, which in turn invites a reconsideration of functional interpretations of sustained neuronal activity in PFC. (nih.gov)
  • Common causes of scotomata include demyelinating disease such as multiple sclerosis (retrobulbar neuritis), toxic substances such as methyl alcohol , ethambutol and quinine , nutritional deficiencies, and vascular blockages either in the retina or in the optic nerve. (wikidoc.org)
  • Common causes of scotomata include demyelinating disease such as multiple sclerosis (retrobulbar neuritis), damage to nerve fiber layer in the retina (seen as cotton wool spots) due to hypertension, toxic substances such as methyl alcohol, ethambutol and quinine, nutritional deficiencies and vascular blockages. (treatheadaches.com)
  • We discuss possible ways to enlarge the size of high-resolution area (isoplanatic patch) in fundus imagers equipped with adaptive optics. (spie.org)
  • Less common, but important because they are sometimes reversible or curable by surgery, are scotomata due to tumors such as those arising from the pituitary gland, which may compress the optic nerve or interfere with its blood supply. (wikipedia.org)
  • We quantified, for the cortical representation of the actually stimulated visual field, the changes in the position and size of the pRFs associated with reduced peripheral stimulation using conventional and advanced pRF modeling. (rug.nl)
  • A scotoma may include and enlarge the normal blind spot. (wikipedia.org)
  • Normally, when we look at a scene with one eye, we do not see a scotoma created by the blind spot or retinal vessels. (arvojournals.org)
  • The presence of this normal scotoma does not intrude into consciousness because it is very small, but it can be demonstrated to oneself by the simplest of clinical methods (such as the one in the blind spot article). (wikidoc.org)
  • The size of the ring was manipulated so that at the beginning of the study, it was detectable about 70 percent of the time, then the researchers modified the size so that it was eventually so small it was completely hidden by the blind spot. (verywell.com)
  • The visual field testing revealed an enlarged blind spot of right eye along with temporal scotoma (figure3) and normal field of left eye (figure4). (ispub.com)
  • Visual field testing demonstrated significant scotomas (blind spots) in all 3 participants while wearing the device, creating a clinically meaningful visual field obstruction in the upper right quadrant. (eurekalert.org)
  • Eye has a blind spot which is also known as scotoma, whereas, the cameras do not have any such limitations. (differencebetween.net)
  • These tests look for flaws and blind spots (scotomas) in your visual field, which is the entire area seen when your gaze is fixed in one direction. (rexhealth.com)
  • An analysis of 132 images indicated that many people wear the device near or overlapping their pupillary axis (a line perpendicular to the surface of the cornea, passing through the center of the pupil), which may induce scotomas and interfere with daily function. (eurekalert.org)
  • Chlorhexidine-alcohol compared with overnight osmotic dilators have different characteristics and severity of dependence diagnostic interview administered by slow development, long life, large size, late reproduction, intensive parental care, and interventional radiology), and blood loss greater than 5 weeks are not necessarily produce better results have been able to throw your testosterone production by male adults is 0.7g/kg/day, out of alignment. (dsaj.org)
  • 2,3) PIC is characterized by multifocal choroidal lesions (yellow-white lesions of the inner choroid and retinal pigment epithelium of approximately 100-300 ìm in size), usually distributed throughout the posterior pole but sparing the peripapillary region. (harvard.edu)
  • The authors note that the study is limited by the small number of participants, who may not be representative of all users, and that a larger sample is needed to identify factors that influence scotoma size and depth. (eurekalert.org)
  • About half the people with small scotomas recover from them completely after some months or years. (stackexchange.com)
  • Diagramming techniques we developed for analyzing prism effects for hemianopic field loss (HFL) 10 yield substantially different conclusions when applied here for PFL because of the enormous difference in the size of the residual field. (arvojournals.org)
  • In the augmented reality task, participants navigated a real-life, human-sized 'mouse maze', which they viewed through cameras in the front of the HMD. (mddionline.com)