Progressive (No Line) Lenses
Progressive lenses are also known as “no-line” bifocals. Progressive lenses actually have three viewing areas – distance, intermediate, and reading vision – and there are no visible lines between the areas. Progressive lenses are very convenient, because you can use them for a variety activities, and most people wear these lenses all day long and use them for everything.
Progressive lenses were introduced in the 1990’s and have since come to dominate the prescription lens market. However, progressive lenses do have some drawbacks. For example, progressive lenses have large blurry areas on the left and right hand side of the middle corridor, and you cannot see through these viewing areas. You must learn to move your head, not your eyes, when looking from side to side through progressive lenses. This requires adaptation, and your adaptation period could be a few days or a few weeks. Some people never adapt to progressive lenses, and some people get headaches and nausea during the adaptation period. However, this occurs to a small minority of people, and most people adapt to progressive lenses and come to love their convenience and ease of use.