Due to a condition known as presbyopia, most middle-aged adults rely on some form of reading prescription to help them see clearly up close. There are many options to help provide clear near vision for those affected by presbyopia, though many of them have drawbacks. Reading glasses are cost-effective and come in a wide range of prescriptions, but constantly putting on or taking off glasses to switch between distance and near work can be aggravating. Lined bifocal glasses can be worn full-time, but many people dislike the noticeable line on their lenses. One of the most popular options for correcting presbyopia is progressive lenses, or no-line bifocals. These multifocal lenses provide clear vision at a wide range of distances without a distracting or disorienting line. Continue reading to learn more about how progressive lenses work.
How do Progressive Lenses Work?
Progressive lenses contain three different prescriptions within a single lens. The top portion of the lens holds the distance prescription for far-away objects. The middle area of the lens contains an “intermediate” prescription. This is one of the unique aspects of progressive lenses, and is useful for viewing objects just beyond arms-length, like a computer or the dashboard. The bottom portion of the lens contains the reading prescription, to be used for objects about 40 centimeters away. The lens contains a gradient, so the three prescriptions transition smoothly without a distracting line separating them.
What are the Benefits of No Line Bifocals?
Many people believe that progressive lenses are the most similar to “natural” vision, providing clear vision at a wide range of prescriptions without the need change glasses. This versatility is perhaps the most appealing thing about these lenses. Most lined bifocals and reading glasses do not provide clear vision for intermediate distances, such as the computer. For many professionals who spend several hours a day on the computer, the intermediate correction of progressive lenses is a necessity. The cosmetic appeal of being line-free is also alluring for many people. Beyond the discreet appearance of no-line bifocals, many people appreciate that there is no disorienting “image jump” or shift in perception when moving your eyes from the top to the bottom of the lenses.
Adapting to Progressive Lenses
Like many new lens designs, progressive lenses can take some time to get used to. There are a few tips to keep in mind to make adjusting to progressives easier. It is important to know that, in order to fit three different prescriptions in one lens, no-line bifocals contain some distortions in the periphery of the lens. Occasionally, when people’s eyes catch these peripheral distortions, it can create a mildly disorienting “swimming” or “fishbowl” effect. You will have your best vision with progressive lenses if you keep your eyes looking through the central portion of the lens. In order to avoid these distortions, remember to point your nose towards the object you are looking at, so your eyes stay in the center. It can also take some time to get used to stairs and curbs with your new progressive lenses. Do not let these adaptations worry you, though. Many people are able to quickly adapt to their progressive lenses and love the versatility of their vision.
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