Presbyopia, or far-sightedness, is a common condition that often begins to affect people over the age of 40. It's comforting to know that developing presbyopia when you already wear glasses for distance vision doesn't mean you now need multiple pairs of specs. This is because of multifocal lenses, which correct both problems, ensuring that you always see well.
At one point, bifocals were widely prescribed, but they were far from all that great; even though they correct problems with both near and distant objects, middle distance is blurred. To rectify this problem, progressive lenses were invented, which give you and intermediate or transition part of the lens allowing you focus on the area between things like the newspaper and far objects like road signs. Progressive lenses, which are also known as no-line lenses, are a type of multifocal lens made with a gradual curvature across the lens surface rather than a sharp line dividing both parts of the lens.
These lenses, although better, can take some time to adjust to. Even though the invisible transition of progressive lenses results in a product that is aesthetically pleasing, the focal areas are quite small because the transitional areas also inhabit space.
Bifocals aren't entirely dated though; they are used to treat kids and teens who have a hard time focusing when reading.
Even though it may seem like an easy fix, avoid purchasing drug store bifocals. A lot of these types of glasses have the same prescription in both lenses, which will not help a lot of people.
If your prescription or fit is off you could end up suffering from headaches, eye strain or even nausea. Presbyopia catches up to the majority of us when we reach a certain age, but it doesn't have to be debilitating. A good pair of multifocals will make a world of difference.