Optical isomers, also known as enantiomers, are a type of stereoisomer that are non-superimposable mirror images of each other. This means that if you were to place one isomer over the other, they would not align perfectly, much like left and right hands. Optical isomers have the same molecular formula and connectivity but differ in the arrangement of atoms in space. These isomers can rotate plane-polarized light in different directions; one will rotate it to the right (dextrorotatory) and the other to the left (levorotatory). This property is crucial in fields like pharmaceuticals, where the effectiveness and safety of a drug can depend on its specific optical isomer.