Bifocal and trifocal prescription lenses are traditional types of multifocal lenses that feature multiple (2 or 3) focal zones separated by distinct, visible lines on the lens. They are commonly referred to as lined multifocal lenses. Progressive lenses, on the other hand, are a modern multifocal lens design that offers numerous focal zones as well, but features no visible lines on the lens. Progressive lenses are commonly referred to as no-line multifocal lenses.