Tinted semi-finished lens having impact resistance and method for manufacturing the same

Abstract

Provided is a method for manufacturing a tinted semi-finished lens that uses polycarbonate, has high light shielding effect, has impact resistance even after polishing, and can have a uniform tint. In particular, in order to provide a tinted semi-finished lens that has the same light shielding at the lens center and the lens edge when a wearer looks through the tinted lens, and furthermore, that seems to have the same light shielding when a third party looks at the wearer, a tinted layer having a uniform thickness and a transparent layer on the back side are integrally formed. Furthermore, in order to provide the impact resistance to either of the resins included in the layers, a low flow resin having a large molecular weight and a short flow length is used. In order to minimize lens distortion and to provide the impact resistance to the lens, the transparent layer employs a resin having the impact resistance, and the transparent layer is formed first and then the tinted layer is formed as an additional layer. Moreover, provided is a method for simultaneously manufacturing two sets of tinted lenses. In the method, two sets of molds are used, a first molded product is obtained in one of the two sets of the molds, and then is transferred to the other mold to form a second molded product, and simultaneously, another first molded product is molded in the first mold.