Optical lens having a hygroscopicity adjusting part

摘要

An optical lens made of plastic comprises an optically functioning part, a flange part disposed around the optically functioning part, and a gate-removed part located at an outer circumferential face of the flange part. The gate-removed part is defined by removing a residual gate part projecting from the outer circumferential face. The surface of the gate-removed part is covered with a hygroscopicity adjusting part. The hygroscopicity adjusting part is made of a material less hygroscopic than the plastic of which the optical lens is made.