Progressive spectacle lens for presbyopia - has intermediate zone with progressive part formed of series of dioptres radiating from common plane joining calotte centres

Abstract

Abstract A spectacle or correction lens is designed for use by sufferers from presbyopia. It possesses all the theoretical advantages of progressive lenses. The lens is easily machined and controlled by the optician or spectacle maker and it remains within easy financial reach of the user. The progressive part of the lens consists of an envelope of a succession of dioptees. The lens has three vision zones which may be part of the concave or convex surfaces or on both. Manufacture involves the use of a rotating dished tool which works across the lens surface. The front surface(2) of the lens has the progressive characteristic and is aspherical. The rear surface may be spherical.

Inventors

No inventors recorded.

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