Color: The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.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).Color Perception Tests: Type of vision test used to determine COLOR VISION DEFECTS.Ultrasonography, Doppler, Color: Ultrasonography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image. This type of ultrasonography is well-suited to identifying the location of high-velocity flow (such as in a stenosis) or of mapping the extent of flow in a certain region.Color Vision Defects: Defects of color vision are mainly hereditary traits but can be secondary to acquired or developmental abnormalities in the CONES (RETINA). Severity of hereditary defects of color vision depends on the degree of mutation of the ROD OPSINS genes (on X CHROMOSOME and CHROMOSOME 3) that code the photopigments for red, green and blue.Hair Color: Color of hair or fur.Eye Color: Color of the iris.Pigmentation: Coloration or discoloration of a part by a pigment.Echocardiography, Doppler, Color: Echocardiography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image.Prosthesis Coloring: Coloring, shading, or tinting of prosthetic components, devices, and materials.Colorimetry: Any technique by which an unknown color is evaluated in terms of standard colors. The technique may be visual, photoelectric, or indirect by means of spectrophotometry. It is used in chemistry and physics. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Skin Pigmentation: Coloration of the skin.Lighting: The illumination of an environment and the arrangement of lights to achieve an effect or optimal visibility. Its application is in domestic or in public settings and in medical and non-medical environments.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.Retinal Cone Photoreceptor Cells: Photosensitive afferent neurons located primarily within the FOVEA CENTRALIS of the MACULA LUTEA. There are three major types of cone cells (red, blue, and green) whose photopigments have different spectral sensitivity curves. Retinal cone cells operate in daylight vision (at photopic intensities) providing color recognition and central visual acuity.Feathers: Flat keratinous structures found on the skin surface of birds. Feathers are made partly of a hollow shaft fringed with barbs. They constitute the plumage.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.Pigments, Biological: Any normal or abnormal coloring matter in PLANTS; ANIMALS or micro-organisms.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.Receptor, Melanocortin, Type 1: A melanocortin receptor subtype found primarily in MELANOCYTES. It shows specificity for ALPHA-MSH and ADRENOCORTICOTROPIC HORMONE. Loss of function mutations of the type 1 melanocortin receptor account for the majority of red hair and fair skin recessive traits in human.Butterflies: Slender-bodies diurnal insects having large, broad wings often strikingly colored and patterned.Anthocyanins: A group of FLAVONOIDS derived from FLAVONOLS, which lack the ketone oxygen at the 4-position. They are glycosylated versions of cyanidin, pelargonidin or delphinidin. The conjugated bonds result in blue, red, and purple colors in flowers of plants.Photography: Method of making images on a sensitized surface by exposure to light or other radiant energy.Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Pattern Recognition, Visual: Mental process to visually perceive a critical number of facts (the pattern), such as characters, shapes, displays, or designs.Retinal Pigments: Photosensitive protein complexes of varied light absorption properties which are expressed in the PHOTORECEPTOR CELLS. They are OPSINS conjugated with VITAMIN A-based chromophores. Chromophores capture photons of light, leading to the activation of opsins and a biochemical cascade that ultimately excites the photoreceptor cells.Sensory Thresholds: The minimum amount of stimulus energy necessary to elicit a sensory response.Spectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.Food Packaging: Containers, packaging, and packaging materials for processed and raw foods and beverages. It includes packaging intended to be used for storage and also used for preparation of foods such as microwave food containers versus COOKING AND EATING UTENSILS. Packaging materials may be intended for food contact or designated non-contact, for example, shipping containers. FOOD LABELING is also available.Meat: The edible portions of any animal used for food including domestic mammals (the major ones being cattle, swine, and sheep) along with poultry, fish, shellfish, and game.Discrimination (Psychology): Differential response to different stimuli.Food Coloring Agents: Natural or synthetic dyes used as coloring agents in processed foods.Blood Flow Velocity: A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.Dental Polishing: Creation of a smooth and glossy surface finish on a denture or amalgam.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)Form Perception: The sensory discrimination of a pattern shape or outline.Agouti Signaling Protein: A secreted protein of approximately 131 amino acids (depending on species) that regulates the synthesis of eumelanin (brown/black) pigments in MELANOCYTES. Agouti protein antagonizes the signaling of MELANOCORTIN RECEPTORS and has wide distribution including ADIPOSE TISSUE; GONADS; and HEART. Its overexpression in agouti mice results in uniform yellow coat color, OBESITY, and metabolic defects similar to type II diabetes in humans.Melanins: Insoluble polymers of TYROSINE derivatives found in and causing darkness in skin (SKIN PIGMENTATION), hair, and feathers providing protection against SUNBURN induced by SUNLIGHT. CAROTENES contribute yellow and red coloration.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Flowers: The reproductive organs of plants.Tooth Discoloration: Any change in the hue, color, or translucency of a tooth due to any cause. Restorative filling materials, drugs (both topical and systemic), pulpal necrosis, or hemorrhage may be responsible. (Jablonski, Dictionary of Dentistry, 1992, p253)Opsins: Photosensitive proteins in the membranes of PHOTORECEPTOR CELLS such as the rods and the cones. Opsins have varied light absorption properties and are members of the G-PROTEIN-COUPLED RECEPTORS family. Their ligands are VITAMIN A-based chromophores.Food Technology: The application of knowledge to the food industry.Attention: Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.Visual Perception: The selecting and organizing of visual stimuli based on the individual's past experience.Ultrasonography, Doppler, Pulsed: Ultrasonography applying the Doppler effect, with velocity detection combined with range discrimination. Short bursts of ultrasound are transmitted at regular intervals and the echoes are demodulated as they return.Immersion: The placing of a body or a part thereof into a liquid.Dental Materials: Materials used in the production of dental bases, restorations, impressions, prostheses, etc.Optical Illusions: An illusion of vision usually affecting spatial relations.Nature: The system of all phenomena in space and time; the totality of physical reality. It is both a scientific and philosophic concept appearing in all historic eras. (Webster 2d; Dr. James H. Cassedy, NLM History of Medicine Division)Visual Cortex: Area of the OCCIPITAL LOBE concerned with the processing of visual information relayed via VISUAL PATHWAYS.Reproducibility of Results: 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.Cues: Signals for an action; that specific portion of a perceptual field or pattern of stimuli to which a subject has learned to respond.Motion Perception: The real or apparent movement of objects through the visual field.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Composite Resins: Synthetic resins, containing an inert filler, that are widely used in dentistry.Reaction Time: The time from the onset of a stimulus until a response is observed.Afterimage: Continuation of visual impression after cessation of stimuli causing the original image.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.Materials Testing: The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.Acrylic ResinsCichlids: Common name for perch-like fish of the family Cichlidae, belonging to the suborder Labroidei, order PERCIFORMES.Bees: Insect members of the superfamily Apoidea, found almost everywhere, particularly on flowers. About 3500 species occur in North America. They differ from most WASPS in that their young are fed honey and pollen rather than animal food.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.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Maxillofacial Prosthesis: A prosthetic appliance for the replacement of areas of the maxilla, mandible, and face, missing as a result of deformity, disease, injury, or surgery. When the prosthesis replaces portions of the mandible only, it is referred to as MANDIBULAR PROSTHESIS.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)Coloring Agents: Chemicals and substances that impart color including soluble dyes and insoluble pigments. They are used in INKS; PAINTS; and as INDICATORS AND REAGENTS.Tooth, Artificial: A fabricated tooth substituting for a natural tooth in a prosthesis. It is usually made of porcelain or plastic.Vision, Ocular: The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain.Visual Fields: The total area or space visible in a person's peripheral vision with the eye looking straightforward.Microspectrophotometry: Analytical technique for studying substances present at enzyme concentrations in single cells, in situ, by measuring light absorption. Light from a tungsten strip lamp or xenon arc dispersed by a grating monochromator illuminates the optical system of a microscope. The absorbance of light is measured (in nanometers) by comparing the difference between the image of the sample and a reference image.Rod Opsins: Photosensitive proteins expressed in the ROD PHOTORECEPTOR CELLS. They are the protein components of rod photoreceptor pigments such as RHODOPSIN.Tooth Bleaching: The use of a chemical oxidizing agent to whiten TEETH. In some procedures the oxidation process is activated by the use of heat or light.Perceptual Closure: The tendency to perceive an incomplete pattern or object as complete or whole. This includes the Gestalt Law of Closure.