optical isomerism

WordReference Random House Unabridged Dictionary of American English © 2026

op′tical isom′erism, [Chem.]

1. Chemistry stereoisomerism in which the isomers are identical in molecular weight and most chemical and physical properties but differ in their effect on the rotation of polarized light. Cf. dextrorotatory, levorotatory, racemism. 

• 1890–95

Collins Concise English Dictionary © HarperCollins Publishers::

optical isomerism noun

1. isomerism of chemical compounds in which the two isomers differ only in that their molecules are mirror images of each other
   See also dextrorotation, laevorotatory

optical isomer noun