A progressive lens design is like a bi- or tri-focal lens in that it corrects more than one vision problem at a time. However, these lenses have no visible lines, improving the cosmetic appearance of ...

Progressive multifocus glasses for all your need. The bottom part of the lens is full-power magnification ... The arbitrarily swingable spring leg design also reduces the squeezing of the glasses ...

Bifocal or trifocal or progressive lenses are really just multiple sets ... piston controlled by three piezoelectric actuators. The design is small, light, can produce plano-convex or plano ...