The trend of presbyopia will gradually appear after the age of 40, but in recent years, due to poor eye habits of modern people, more and more people have presbyopia reported in advance. Therefore, the demand for bifocals and progressives has also increased. Which of these two lenses is the most preferred for people with myopia and presbyopia?
1. Bifocals
Bifocals have two degrees. Generally, the upper part is used to see far areas, such as driving and walking; the lower part is used to see the near, such as reading a book, playing with a mobile phone, etc. When bifocal lenses first came out, they were indeed regarded as the gospel for people with short-sightedness and presbyopia, eliminating the trouble of frequent removal and wearing, but as people used them, they found that bifocal lenses also have many disadvantages.
First of all, the biggest disadvantage of this kind of lenses is that there are only two degrees, and there is no smooth transition between looking far and near, so it is easy to produce prism phenomenon, which is often called "jump image". And it is easy to fall when wearing it, which is less safe for wearers, especially elderly wearers.
Secondly, the another obvious disadvantage of bifocal lenses is that if you look carefully at bifocal lenses, you can see a clear dividing line between the two degrees on the lens. So in terms of aesthetics, it may not be very beautiful. In terms of privacy, due to the obvious characteristics of bifocal lenses, it may be awkward for younger wearers.
Bifocal lenses eliminate the trouble of frequent removal and wearing of myopia and presbyopia. They can see clearly in the distance and near, and the price is relatively cheap; but the middle distance area may be blurred, and the safety and aesthetics are not good.
2. Progressives
Progressive lenses have multiple focal points, so like bifocal lenses, they are suitable for people with short-sightedness and presbyopia. The upper part of the lens is used to see distance, and the lower is used to see near. But unlike bifocal lenses, there is a transition zone ("progressive zone") in the middle of the progressive lens, which allows us an adaptive degree area to see the distance from far to near. In addition to the top, middle, and bottom, there is also a blind area on both sides of the lens. This area cannot see objects, but it is relatively small, so it basically does not affect the use.
In terms of appearance, progressive lenses are basically indistinguishable from single vision glasses, and the dividing line will not be easily seen, because only the wearer of progressive lenses can feel the difference in power in different areas. It is more suitable for those who want to protect their privacy. In terms of functionality, it can meet the needs of seeing far, middle and near. It is more comfortable to look at the middle distance, there is a transition zone, and the vision will be clearer, so in terms of use effect, progressives are also better than bifocals.
Post time: Jun-30-2023