If you suffer from presbyopia, a condition characterized by blurred vision in the near sight, in addition to myopia, hyperopia or astigmatism you may want to consider bifocals to assist you with near and far vision. Essentially, bifocals are two lenses combined together to address both vision problems. When they were first developed, bifocals were created with one lens on top of another, so that users had to use a particular segment of the lens for a specific purpose.
Typical bifocals have concrete lines that separate the different lenses. Progressive lenses offer the same features, but without the lines. This type of lens is useful for all corrections but does not utilize any separation of segments between the different prescriptions.