Afterimage: Continuation of visual impression after cessation of stimuli causing the original image.Illusions: The misinterpretation of a real external, sensory experience.Color Perception: Mental processing of chromatic signals (COLOR VISION) from the eye by the VISUAL CORTEX where they are converted into symbolic representations. Color perception involves numerous neurons, and is influenced not only by the distribution of wavelengths from the viewed object, but also by its background color and brightness contrast at its boundary.Color Vision: Function of the human eye that is used in bright illumination or in daylight (at photopic intensities). Photopic vision is performed by the three types of RETINAL CONE PHOTORECEPTORS with varied peak absorption wavelengths in the color spectrum (from violet to red, 400 - 700 nm).Perceptual Closure: The tendency to perceive an incomplete pattern or object as complete or whole. This includes the Gestalt Law of Closure.Color: The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.Figural Aftereffect: A perceptual phenomenon used by Gestalt psychologists to demonstrate that events in one part of the perceptual field may affect perception in another part.Adaptation, Ocular: 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)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.Flicker Fusion: The point or frequency at which all flicker of an intermittent light stimulus disappears.Size Perception: The sensory interpretation of the dimensions of objects.Contrast Sensitivity: The ability to detect sharp boundaries (stimuli) and to detect slight changes in luminance at regions without distinct contours. Psychophysical measurements of this visual function are used to evaluate visual acuity and to detect eye disease.Vision, Binocular: The blending of separate images seen by each eye into one composite image.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.Psychophysics: The science dealing with the correlation of the physical characteristics of a stimulus, e.g., frequency or intensity, with the response to the stimulus, in order to assess the psychologic factors involved in the relationship.Nystagmus, Optokinetic: Normal nystagmus produced by looking at objects moving across the field of vision.Click Chemistry: Organic chemistry methodology that mimics the modular nature of various biosynthetic processes. It uses highly reliable and selective reactions designed to "click" i.e., rapidly join small modular units together in high yield, without offensive byproducts. In combination with COMBINATORIAL CHEMISTRY TECHNIQUES, it is used for the synthesis of new compounds and combinatorial libraries.Quantum Dots: Nanometer sized fragments of semiconductor crystalline material which emit PHOTONS. The wavelength is based on the quantum confinement size of the dot. They can be embedded in MICROBEADS for high throughput ANALYTICAL CHEMISTRY TECHNIQUES.Cadmium Compounds: Inorganic compounds that contain cadmium as an integral part of the molecule.Selenium Compounds: Inorganic compounds that contain selenium as an integral part of the molecule.Journal Impact Factor: A quantitative measure of the frequency on average with which articles in a journal have been cited in a given period of time.Television: The transmission and reproduction of transient images of fixed or moving objects. An electronic system of transmitting such images together with sound over a wire or through space by apparatus that converts light and sound into electrical waves and reconverts them into visible light rays and audible sound. (From Webster, 3rd ed)Medicine in Literature: Written or other literary works whose subject matter is medical or about the profession of medicine and related areas.Image Processing, Computer-Assisted: 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.Racism: Differential treatment or unequal access to opportunities, based on group membership such as origin or ethnicity.History, 19th Century: Time period from 1801 through 1900 of the common era.History, 20th Century: Time period from 1901 through 2000 of the common era.Multimedia: Materials, frequently computer applications, that combine some or all of text, sound, graphics, animation, and video into integrated packages. (Thesaurus of ERIC Descriptors, 1994)Journalism: The collection, preparation, and distribution of news and related commentary and feature materials through such media as pamphlets, newsletters, newspapers, magazines, radio, motion pictures, television, and books. While originally applied to the reportage of current events in printed form, specifically newspapers, with the advent of radio and television the use of the term has broadened to include all printed and electronic communication dealing with current affairs.Journalism, Medical: The collection, writing, and editing of current interest material on topics related to biomedicine for presentation through the mass media, including newspapers, magazines, radio, or television, usually for a public audience such as health care consumers.Circadian Rhythm: The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs and stimuli, hormone secretion, sleeping, and feeding.Newspapers: Publications printed and distributed daily, weekly, or at some other regular and usually short interval, containing news, articles of opinion (as editorials and letters), features, advertising, and announcements of current interest. (Webster's 3d ed)Periodicals as Topic: A publication issued at stated, more or less regular, intervals.Motion Pictures as Topic: The art, technique, or business of producing motion pictures for entertainment, propaganda, or instruction.Holidays: Days commemorating events. Holidays also include vacation periods.ArtPaintingsPolandPatient Care Team: Care of patients by a multidisciplinary team usually organized under the leadership of a physician; each member of the team has specific responsibilities and the whole team contributes to the care of the patient.Equilibrative-Nucleoside Transporter 2: A subtype of equilibrative nucleoside transporter proteins that is insensitive to inhibition by 4-nitrobenzylthioinosine.Electroplating: Coating with a metal or alloy by electrolysis.Tanning: A process of preserving animal hides by chemical treatment (using vegetable tannins, metallic sulfates, and sulfurized phenol compounds, or syntans) to make them immune to bacterial attack, and subsequent treatments with fats and greases to make them pliable. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Chromium: A trace element that plays a role in glucose metabolism. It has the atomic symbol Cr, atomic number 24, and atomic weight 52. According to the Fourth Annual Report on Carcinogens (NTP85-002,1985), chromium and some of its compounds have been listed as known carcinogens.Chromium Compounds: Inorganic compounds that contain chromium as an integral part of the molecule.Image Interpretation, Computer-Assisted: Methods developed to aid in the interpretation of ultrasound, radiographic images, etc., for diagnosis of disease.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Eye Diseases: Diseases affecting the eye.Vitreous Detachment: Detachment of the corpus vitreum (VITREOUS BODY) from its normal attachments, especially the retina, due to shrinkage from degenerative or inflammatory conditions, trauma, myopia, or senility.Retinal Detachment: Separation of the inner layers of the retina (neural retina) from the pigment epithelium. Retinal detachment occurs more commonly in men than in women, in eyes with degenerative myopia, in aging and in aphakia. It may occur after an uncomplicated cataract extraction, but it is seen more often if vitreous humor has been lost during surgery. (Dorland, 27th ed; Newell, Ophthalmology: Principles and Concepts, 7th ed, p310-12).Vitreous Body: 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.Iatrogenic Disease: Any adverse condition in a patient occurring as the result of treatment by a physician, surgeon, or other health professional, especially infections acquired by a patient during the course of treatment.Vitrectomy: Removal of the whole or part of the vitreous body in treating endophthalmitis, diabetic retinopathy, retinal detachment, intraocular foreign bodies, and some types of glaucoma.