Apochromatic lens: Compound lens corrected for chromatic aberration, i.e. the three primary colours , red, green and blue are corrected. Also called Apochromat.

矫正色的复合式透镜：即是红、三原色的色都已矫正。

By chiseling a BOL on a surface of a lens, a apochromatic system is composed, which actualizes the system's apochromatism, as well as revising primary aberration.

并光学面刻画在透镜的表面，在校正系统初级像的同时，实现了系统的复消色。