achromasia ach·ro·ma·si·a (āk’rō-mā’zē-ə, -zhə)
Pallor associated with the hippocratic facies of extremely severe and chronic illness.
. noun Also called achromatic lens. a lens designed to bring light of two chosen wavelengths to the same focal point, thus reducing chromatic aberration Compare apochromat a person who has no colour vision at all and can distinguish only black, white, and grey. The condition is very rare
a person unable to perceive color.
Optics. free from color. able to emit, transmit, or receive light without separating it into colors. Biology. (of a cell structure) difficult to stain. Music. without accidentals or changes in key. Historical Examples achromatic lenses are used in all high-grade optical instruments such as telescopes and microscopes. Physics Willis Eugene Tower If not, the substitution […]
- Achromatic colour
noun (physics) colour, such as white, black, and grey, that is devoid of hue See colour (sense 2)