Presbyopia affects nearly everyone in their 40s. This vision condition means that our focusing system gets lazy and our near vision becomes compromised. We start relying on a reading prescription to help us see up close, whether it is with reading glasses, multifocal contact lenses, or bifocal glasses. One of the most popular options for vision correction in presbyopia is called progressive lenses or no-line bifocals. This special lens design can provide clear vision at a wide range of distances. Many people consider progressive lenses to be the closest alternative to a natural focusing ability. Continue reading to learn all about progressive lenses and the benefits they offer.
Progressive lenses incorporate a power gradient which provides three different prescriptions in one lens. At the top of the lens is the distance prescription, which is used to view far-away objects. The middle portion of the lens contains an “intermediate” prescription. This prescription is designed for looking at objects just beyond arm’s length, like a computer screen or the dashboard of a car. Towards the bottom of the lens there is a reading prescription. This portion of the lens is similar to a traditional lined bifocal in that it contains a prescription specifically to be used for up-close objects at about 16 inches. The lens design of a no-line bifocal provides a smooth transition between the three optical powers of the lens, allowing you to easily view objects at a wide variety of distances.
In order to fit three different prescriptions into the central portion of the lens, the peripheral portion of the lens may contain some distortions. While this is not noticeable to other people looking at your glasses, you may notice the distortions if you accidentally look through the sides of the lenses rather than through the center. Some people describe it as a “swimming” or “fishbowl” effect. While it can be initially distracting, this property is easily adapted to.
There is a big cosmetic appeal for no-line bifocals. Many people enjoy the fact that the lenses can provide clear vision for reading and near work without the distracting appearance of a bifocal line. These lenses are also more convenient than reading-only glasses that must be put on and removed every time something needs to be read or closely examined. For those professionals affected by presbyopia who spend a lot of time on the computer, progressive lenses are an excellent option – they allow for the flexibility of viewing objects far away in the office, up close on the desk, and on the computer screen all with one pair of glasses.
While some people struggle to adapt to the progressive lens design, including the peripheral distortions, there are several tips that can ease the process. First and foremost, remember to look through the central portion of the lens. If you are trying to look at an object that is off to your side, point your nose towards the object first so your eyes are directly facing the correct direction. This reduces the fishbowl effect of the peripheral distortions. Also remember to take caution with stairs and steps when you are first getting used to the lenses, as your depth perception may be off when looking through the bottom of the lenses. Most people are able to easily and happily adjust to progressive lenses within a few weeks of wear.