| visual threshold | Threshold of visual sensation, the minimal light intensity evoking a visual sensation. Synonym: achromatic threshold, minimum light threshold. (05 Mar 2000) |
|---|---|
| visual violet | A visual pigment, composed of 11-cis-retinal bound to an opsin, found in the cones of the retina. Synonym: visual violet. Origin: G. Ion, violet, + ops, eye, + -in (05 Mar 2000) |
| primary visual area | Area of the occipital lobe concerned with vision. (12 Dec 1998) |
| primary visual cortex | See: visual cortex. (05 Mar 2000) |
| secondary visual area | Area of the occipital lobe concerned with vision. (12 Dec 1998) |
| secondary visual cortex | See: visual cortex. (05 Mar 2000) |
| evoked potentials, visual | The electric response evoked in the cerebral cortex by visual stimulation or stimulation of the visual pathways. (12 Dec 1998) |
| unformed visual hallucination | Hallucination composed of sparks, lights, or bursting spheres of light. (05 Mar 2000) |
| formed visual hallucination | <psychiatry> Hallucination composed of scenes, often landscapes. (05 Mar 2000) |
| functional visual loss | An apparent loss of visual acuity or visual field with no substantiating physical signs; often due to a natural concern about visual loss combined with suggestibility and a fear of the worst; best treated with reassurance. (05 Mar 2000) |
| acridine yellow | A faintly yellow solution with strong bluish-violet fluorescence; used as a topical antiseptic and as a fluorescent stain in histology. Synonym: 5-aminoacridine hydrochloride, 9-aminoacridine hydrochloride. (05 Mar 2000) |
| acute yellow atrophy of the liver | A lesion in which there is extensive and rapid death of parenchymal cells of the liver, sometimes with fatty degeneration of the size of the organ; the necrosis may result from fulminant viral infection or chemical poisoning; associated with jaundice. Synonym: acute parenchymatous hepatitis, Rokitansky's disease. (05 Mar 2000) |
| brilliant yellow | An indicator dye that changes from yellow to orange or red at pH 6.4 to 8.0. (05 Mar 2000) |
| butter yellow | C6H5N:NC6H4N(CH3)2;a fat-soluble yellow dye (MW 225) that has hepatic carcinogenic action in experimental animals; used as an indicator of pH (red, at pH 2.9, yellow at pH 4.0). Synonym: dimethylaminoazobenzene, methyl yellow. (05 Mar 2000) |
| martius yellow | C10H6N2O5; 2,4-dinitro-alpha-naphthol;an acid dye used as a plasma stain in plant and animal histology, and as a light filter for photomicrography. Origin: Karl A. Martius, Ger. Chemist, *1920 (05 Mar 2000) |