Progressive lens

摘要

A progressive lens with a continuous surface comprises three substantially constant power areas. A first such area is mathced to far vision, a second to near vision and a third, between the first and second areas, to intermediate vision. Respective progressively varying power areas lie between the first and third areas and between the third and second areas. A predetermined progress meridian passing through these substantially constant power areas may have substantially umbilical parts between the substantially constant power areas.