visual achromatism

visual achromatism

[′vizh·ə·wəl ā′krō·mə‚tiz·əm] (optics) In an optical system, the removal of chromatic aberration or chromatic differences of magnification between light at the wavelength of the Fraunhofer C line at 656.3 nanometers and the F line at 486.1 nanometers in order to minimize these defects at wavelengths at which the human eye is most sensitive. Also known as optical achromatism.