PROGRESSIVE LENS

摘要

A progressive ophthalmic lens element including a lens surface having an upper viewing zone having a surface power corresponding to distance vision, a lower viewing zone having a greater surface power than the upper viewing zone to achieve a refracting power corresponding to near vision; and an intermediate zone extending across the lens element having a surface power varying from that of the upper viewing zone to that of the lower viewing zone and including a corridor of relatively low surface astigmatism; the corridor exhibiting a power progression from that of the upper viewing zone to that of the threshold of the lower viewing zone, the corridor and lower viewing zone exhibiting a power progression profile having at least two segments the slopes of which related at least in part to the prescribed addition power and/or the depth of focus of the wearer.