Patent attributes
A novel method for manufacturing a contact lens in which wearing comfort and stability in the circumferential direction that are aimed at can be achieved consistently with a high degree of accuracy irrespective of a profile of an optical zone. An optical zone provided in a center of a lens has a concave rear surface optical zone substantially matching a surface profile of a cornea and has a convex front surface optical zone imparting required spherical diopter power and geometrical center thickness, and a face of either the rear surface optical zone or the front surface optical zone is designed to impart thereto cylindrical power and axial angle required for a toric surface. Furthermore, a junction thickness is established in a joint zone that connects the optical zone with a peripheral zone at multiple sites in a circumferential direction about a geometrical lens center axis of the optical zone. Position of the joint zone is determined on the circumference from profiles established on the rear surface optical zone and the front surface optical zone so as to connect points satisfying the junction thickness thusly established.
