\Op"tic*al*ly\, adv.
By optics or sight; with reference to optics.
{Optically active}, {Optically inactive} (Chem. Physics),
   terms used of certain metameric substances which, while
   identical with each other in other respects, differ in
   this, viz., that they do or do not produce right-handed or
   left-handed circular polarization of light.
{Optically positive}, {Optically negative}. See under
   {Refraction}.