Presbyopia, or far-sightedness, is a common condition that usually starts to affect those over the age of 40. If you already struggle with distance vision, and are later on diagnosed with presbyopia, you won't have to carry a separate pair of reading glasses. Multifocal lenses, which rectify problems with both near and far sight, allow you to see well at all times, with one pair of glasses.
At one point, bifocals were the popular fix, but they have a significant shortcoming; even though they help you to focus on both near and distant objects, middle distance is blurred. To rectify this problem, progressive lenses were developed. These give you a transition region allowing you focus on the area between near and far distances. Progressive or no-line lenses are a type of multifocal lens featuring a subtly curved lens surface instead of a noticeable line separating the two areas of the lens. This creates not just better vision at all distances, but also good transitions between the two.
Progressive lenses, although better, may require a small period of time to adjust to. While the invisible lens curve results in a product that is elegant, the lens's areas of focus are small, because they all need to fit.
While these days, these progressive lenses (sometimes called trifocals) are for presbyopia, bifocals are still used to help young patients with eye problems such as eye teaming, or being unable to focus while reading, which in turn, can lead to headaches.
Although it may appear to be an easy solution, avoid buying drug store bifocals. Most of these types of glasses have the same prescription in both lenses, which will not help a lot of people.
A badly fitted pair of glasses can lead to eye strain, discomfort and headaches. At a certain age, most people will not be able to avoid presbyopia. But it's important to know that good, multifocal lenses can enrich your vision, and your life.