Presbyopia, or far-sightedness, is a common condition that often begins to affect those who are 40 or older. It's comforting to know that developing presbyopia when you already wear glasses for distance vision doesn't mean you now need two pairs of specs. Multifocal lenses let you have good vision always, correcting your presbyopia and myopia at once.
At one point, bifocals were widely prescribed, but they have a major flaw; even though they correct problems with both near and distant objects, everything else is blurred. To create something better, progressive lenses were developed, which give you a transition region that allows you focus on the area between things like the books you read and far objects like road signs. Progressive lenses, which are also called no-line lenses, are a type of multifocal lens that have a subtle curvature across the lens surface rather than a noticeable line separating the two areas of the lens. This provides not only clearer vision at all distances, but also nice, easy transitions in between.
Progressive lenses may require some time to adjust to. Despite the fact that the gentle lens curve is more aesthetically pleasing, the focal areas are quite small because more lens space is used for the transitional areas.
Bifocals are still used though; they are used to treat children and teenagers who experience eye strain, which is the result of a difficulty focusing while reading.
Although it may seem like a quick fix, avoid buying pharmacy bifocals. Most of these ''ready-made'' glasses are one-size-fits-all, which means that the both lenses contain the same prescription and are not customized for the wearer.
If you've been fitted with an inaccurate prescription you could end up suffering from eye strain, discomfort and nausea. Unfortunately, presbyopia is a reality of our bodies' aging process. But keep in mind that multifocal lenses can make all the difference.