A low-birefringent organic optical component comprising a polymer prepared by polymerizing a racemic mixture of the monomer with an asymmetric spiro ring represented by general formula (1) as an essential ingredient; wherein ring A represents a monocyclic or polycyclic organic group, wherein two ring As are mutually bound each other via a spiro bond to form a spiro ring which has a molecular asymmetric structure; n is an integer of 0 to 10; X.sub.1 and Y.sub.1 are binding groups; and Z.sub.1 is a polymerization-active group. The component has excellent transparency, mechanical strength and heat resistance, as well as a low birefringence.