What is a bifocal lens and what are the features of a bifocal lens?
A bifocal lens is a lens that has two different powers within it. An example of this is demonstrated in the Ultra 3x-6x hand magnifier. The large portion of the lens has a magnification of 3x, and the smaller lens, which is molded as an integral part of the larger lens, has a magnification of 6x. In spectacle lenses, the upper portion of the lens has a proper prescription for distance viewing and the lower portion has the proper RX for close up viewing.