Bifocal lenses, 
Bifocal lenses used to be the only option for people with presbyopia  who also require a correction for myopia, hyperopia and/or astigmatism. They are lenses that carry two distinct optical powers in each lens, usually separated by a visible line. Midrange vision (at arms length) is compromised as there is no set correction for that distance in a bifocal. A trifocal includes a section dedicated to midrange vision. The bifocal is an old technology- progressive lenses are now the new option for better aesthetics and comfort.