| 摘要 |
A mold assembly for forming a lens blank (62) which gives a contact lens (80), the mold assembly comprising an upper and a lower mold half (2; 4) which cooperate with each other to define a substantially fluid-tight mold cavity (46) when the two mold haves are assembled together, the mold cavity being filled with a monomer liquid (60) which is polymerized to provide the lens blank that is to be subjected to a cutting operation for forming a base and a front curved surface (68; 78) of the contact lens, wherein the improvement comprises: the upper mold half (4) including a flexible thin-walled portion (12) which has a downwardly convex shape and which partially defines the mold cavity (46), the thin-walled portion being deformable to absorb expansion or shrinkage of the monomer liquid during polymerization thereof in the mold cavity; and the lower mold half (2) including a base portion (32) at which the lower mold half is clamped by a chuck of a lathe during the cutting operation, and a mold portion (30) having a molding surface (38) which is provided with lens blank holding means (40, 42, 52) for holding the lens blank on the lower mold half, the lens blank being formed in the mold cavity defined by and between the upper and lower mold halves. <IMAGE>
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