| PTAT | pure tone average threshold |
|---|---|
| ST | esotropia; scala tympani; scaphotrapezoid; sclerotherapy; sedimentation time; semitendinosus; sensor... |
| TD | tabes dorsalis; tardive dyskinesia; T-cell dependent; temporary disability; terminal device; tetanus... |
| TDT | terminal deoxynucleotidyltransferase; thermal death time; tone decay test; tumor doubling time |
| TONE | tilted optimized nonsaturating excitation |
| colour blindness | A sex-linked inherited condition where there is an inability to distinguish colours. Very few women are colour blind, but up to 10% of all men have some degree of colour blindness. The most common for is red-green colour blindness. The second most common is blue-yellow. Inheritance: sex-linked (X chromosome). (27 Sep 1997) |
|---|---|
| colour constancy | Unchanging perception of the colour of an object despite changes in lighting or viewing conditions. (05 Mar 2000) |
| colour-contrast microscope | <instrument> A type of microscope in which the condenser stop is of one colour and the annulus is a complement of it so that unstained objects are observed in one colour on a field of the other. (05 Mar 2000) |
| Colour Index | A publication concerned with the chemistry of dyes, with each listed dye identified by a five-digit Colour Index number, e.g., methylene blue is Colour Index 52015. (05 Mar 2000) |
| colour match | The result of adjusting colour mixtures until all visually apparent differences are minimal. (05 Mar 2000) |
| colour perception | The visual awareness of any particular hue or achromatic colour. (12 Dec 1998) |
| colour radical | The part of a visibly coloured molecule responsible for light absorption over a range of wavelengths thus giving rise to the colour. By extension the term may be applied to UV or IR absorbing parts of molecules. Do not confuse with chromatophores. (18 Nov 1997) |
| colour scotoma | An area of depressed colour vision in the visual field. (05 Mar 2000) |
| colour sense | The ability to perceive variations in hue, luminosity, and saturation of light. (05 Mar 2000) |
| colour solid | A schematic arrangement of colour in space, the attributes of hue, saturation, and brightness being represented by cylindrical coordinates. (05 Mar 2000) |
| colour spectrum | The continuum of colours that white light forms on passing through a prism or diffraction grating. Synonym: colour spectrum. (05 Mar 2000) |
| colour taste | A form of synesthesia in which the colour sense and taste are associated, with stimulation of either sense inducing a subjective sensation in the associated sense. Synonym: pseudogeusesthesia. (05 Mar 2000) |
| colour therapy | A form of phototherapy using colour to influence health and to treat various physical or mental disorders. The colour rays may be in the visible or invisible spectrum and can be administered through coloured lights or applied mentally through suggestion. (12 Dec 1998) |
| colour triangle | A graph on which chromaticity coordinates are plotted. (05 Mar 2000) |
| colour vision defects | Mild to severe impairment in the ability to discriminate or differentiate hues. This disorder may be acquired as a result of diseases of the cones or x chromosome-linked where there is an abnormality but not a complete absence of one of the cone pigments. (12 Dec 1998) |