corrected for spherical aberration at two wavelengths or colors and for chromatic aberration at three wavelengths.
Origin of apochromatic
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
(of a lens) almost free from spherical and chromatic aberration
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012