What is optical isomerism? What is the necessary and sufficient condition for a molecule to exhibit optical isomerism ?

Explanation

Optical isomerism : Certain compounds rotate the plane of plane polarised light when it is passed through their solutions. Such compounds are called optically active compounds. Compounds which behave differently toward plane polarised light are called optically isomers and the phenomenon is called optical isomerism. Asymmetry of the molecule in the necessary and suflicient condition for a molecule to exhibit optical isomerism.