To obtain excellent shock resistance and scratch resistance and to improve work efficiency by using a UV-curing resin for a plastic lens base material.

The plastic lens base material consists of a UV-curing resin, which contains polyfunctional carbon-carbon unsatd. compd. (polyethylene), polyfunctional thiol (polythiol), photoinitiator, etc., as the components. As for the polyethylene, an alloylether resin is used. As for the polythiol, thioglycol acid is used. To form a primer layer, it is necessary to apply a coating material for the primer layer on the lens and irradiate the layer with UV rays for 1 to 120sec. If the irradiation time is less than 1sec, the coating film is not sufficiently hardened. If the time exceeds 120sec, the plastic lens changes its color into yellow. The primer layer is required to have 0.1 to 10μm film thickness. If the layer is thinner than 0.1μm, shock resistance of the layer largely decreases. If the layer is thickner than 10μm, heat resistance of the film decreases.