Progressive lenses are no-line multifocal eyeglass lenses that look exactly the same as single vision lenses. In other words, progressive lenses will help you see clearly at all distances without those annoying (and age-defining) "bifocal lines" that are visible in regular bifocals and trifocals.
The power of progressive lenses changes gradually from point to point on the lens surface, providing the correct lens power for seeing objects clearly at virtually any distance.
Bifocals, on the other hand, have only two lens powers — one for seeing distant objects clearly and a second power in the lower half of the lens for seeing clearly at a specified reading distance. The junction between these distinctly different power zones is defined by a visible "bifocal line" that cuts across the center of the lens.
Progressive lenses sometimes are called "no-line bifocals" because they don't have this visible bifocal line. But progressive lenses have a significantly more advanced multifocal design than bifocals or trifocals.
Premium progressive lenses (such as Varilux lenses) usually provide the best comfort and performance, but there are many other brands as well. Your eye care professional can discuss with you the features and benefits of the latest progressive lenses and help you find the best lenses for your specific needs.