#achromatic

• Achromatic — An optical system or lens specially corrected to minimize chromatic aberration, allowing light rays of different colors to focus at the same point; in a medical sense, an individual affected by achromatopsia, characterized by the complete lack of color perception, seeing the world only in shades of gray, white, and black.
• Achromatic lens — The feminine form of the term achromat; describes a lens or optical structure capable of transmitting light without breaking it down into component colors at the edges. In medicine, it refers to a female individual affected by total achromatopsia or, in biology, to cells or tissues that do not bind standard histological dyes.
• Achromatic — Devoid of color, chromaticaly neutral, or not causing the decomposition of white light into its component spectral colors. In visual arts and design, it refers to color schemes based strictly on white, black, and intermediate shades of gray, whereas in optics it indicates a system capable of refracting light without parasitic dispersion.
• Anachromatic — Not chromatic; an optical system, lens, or transparent medium that does not produce chromatic aberrations or that has been partially or totally corrected against light dispersion. In a precise structural sense, it describes the property of a device to transmit light beams without separating the component colors of the visible spectrum, guaranteeing a faithful and clear rendering of the edges of projected images.