Plastic lens, lens module, lens injection mould

The invention provides a plastic lens, a lens module, a lens injection mould. The plastic lens comprises an effective surface which is the optical surface of the lens; and a flange which is the peripheral part of the lens. The center of the effective surface is not superposed by the center of the flange. In order to compensate the concentric error generated when the lens having a non-axisymmetric structure is configured on a lens barrel in advance, the center of the lens effective surface is moved and thus not superposed by the center of the lens barrel. By making the lens in a way to have a deviation between the center of the effective surface and the center of the flange, the lens is enabled to make the distortion error after as assembly minimized or even eliminated. Minimization of optical performance deterioration of the lens is taken into account.