Abstract: PCT No. PCT/JP78/00011 Sec. 371 Date June 25, 1979 Sec. 102(e) Date June 20, 1979 PCT Filed Oct. 25, 1978, PCT Pub. No. WO 79/00235 PCT Pub. Date May 3, 1979.A Mold for injection molding suitable for the production of those molded synthetic resin articles such as lenses and prisms which are required to be homogeneous and isotropic, in which first and second gates (3, 4) are provided between runner (2) and cavity (1), said first gate (3) having a cross-sectional area smaller than that of runner (2) and connecting to second gate (4); said second gate (4) extending from first gate (3) with the width progressively increasing in a form simulating the shoulder part of a coathanger to meet cavity (1) and having constriction (5) provided halfway to the cavity.