The constant development of medical technology allows millions of people around the world to regain their lost vision and lead a full-fledged lifestyle. One of the well-proven ways to get away from presbyopia, which occurs with age in most people, is to use two or more pairs of glasses. Of course, this is not always convenient, and bifocal glasses come to the rescue, which combine the properties of two pairs.
Usually, the upper half of the glass in such glasses allows you to clearly see distant objects, and the lower half to distinguish objects that are nearby. There can be more such glasses in glasses, then bifocal glasses can become trifocal or even multifocal.
The idea of ​​their creation was prompted by nature itself, some fish species have bifocal vision, which allows you to clearly see objects at the bottom of the reservoir and at the same time carefully monitor the approach of
birds of prey from above. It is believed that the first bifocal glasses were invented by
Benjamin Franklin, who combined two pairs of glasses in one.
An interesting development of this idea was proposed by a scientist from Israel, Zeev Zalevsky, who combined the glasses in such a way that the bifocal glasses became much more convenient in operation. In his glasses there is no sharp border between the glasses. The light reflected from distant and close objects is focused in one continuous stream, which covers the entire retina. This allows you to see all objects equally well. In such glasses, eyes are less tired, and it will take less time to adapt to them.
When testing them, an interesting feature was noted. It turned out that they can correct both vision defects. That is, these glasses can not only cope with this age-related illness, they are very useful for preventive purposes.
The development of high technologies also provides additional opportunities for the development of the issue of preservation of vision. Bifocal glasses are being developed in their electronic version. In this case, a liquid crystal screen is inserted between the two glasses, which transfers the image to us.
In the case of the electronic version of bifocal glasses, the developers are faced with the task of increasing image quality. Also interesting are the parameters of the novelty for increasing or decreasing the image, as well as autofocus. The first prototypes were provided by PixelOptics, which does not stop research in this area.
After consultation with your doctor, you can purchase bifocal glasses. The price for them varies depending on the firm of the manufacturer and the quality of the goods. But the main thing in this matter is the correctly selected parameters of such points. The final adaptation time depends on this, which can take up to ten days from the start of use.
If you work longer with objects that are close, then the bottom glass should be larger than the top. And, accordingly, when working with distant objects, buy glasses with a larger area of ​​the upper glasses. This will help you quickly adapt to the new product and lead a full lifestyle.