| eye colour | Colour of the iris. (12 Dec 1998) |
|---|---|
| Young-Helmholtz theory of colour vision | A theory that there are three colour-perceiving elements in the retina: red, green, and blue. Perception of other colours arises from the combined stimulation of these elements; deficiency or absence of any one of these elements results in inability to perceive that colour and a misperception of any other colour of which it forms a part. Synonym: Helmholtz theory of colour vision. (05 Mar 2000) |
| ultrasonography, doppler, colour | Ultrasonography applying the doppler effect, with the superposition of flow information as colours 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. (12 Dec 1998) |
| Farnsworth-Munsell colour test | A test for colour perception; the task is to arrange 84 colour disks (in four separate racks of 20-22 disks) in a sequence with minimal separation of hue between adjacent disks. (05 Mar 2000) |