BALANCED PROGRESSIVE LENS

摘要

A progressive ophthalmic lens element including a lens surface havingan upper viewing zone having a surface power to achieve a refracting power corresponding to distance vision,a lower viewing zone having a different surface power than the upper viewing zone to achieve a refracting power corresponding to near vision; andan 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 one or more of the upper, intermediate and lower viewing zones being designed optically to reduce or minimise a selected measure of blur for the corresponding range of object distances; andat least a portion of the peripheral region of the surface of the ophthalmic lens element being designed to reduce or minimise one or more surface characteristics known to correlate with the sensation of swim.