Bifocals are some of the most popular multifocal lenses that some specific wearers tend to select. They can to the greatest extent help wearers see objects clearly. Also, they can help prevent the emergence of some problems. However, sometimes, they are not perfect as people have thought of. As for sufferers of age-related eye problems, as presbyopia, they usually choose bifocals.
In fact, among the family of multifocal lenses, trifocals are very special and outstanding. As their names indicate, there are three prescriptions in each of these lenses. Wearers can use these lenses as they need, no matter where or what to see. As for sufferers of presbyopia, trifocals are very practical and effective. As it has mentioned that there are three prescriptions in each pair of trifocals, there are different diopters that are responsible for long, intermediate and short distance vision.
The structure of trifocals is also very special. The bottom parts are composed of two areas, each of which is responsible for short and intermediate distance vision. Such design is the result of considering of people’s daily habits, such as reading etc.
In the middle part of the lenses is the area that is repossible for intermediate distance vision. It can not correct the vision, but the pictures of the objects can be expanded by the lens. Such lenses are nice for computer users.
Lastly, the top part is responsible for the vision of long distance. Myopia and farsightedness can also be corrected in this part if some prescriptions are made.
Presbyopia, a Latin word, which is related to aging, means sight loss with aging process. Especially for those who are over40 such problem is a very common problem. Some methods, as surgery, are used to deal with it. In the meantime, trifocals are also good alternatives.
Trifocals are combination of three lenses with three prescriptions. Sometimes, wearers can also choose some progressive glasses which include PALs, varifocal lenses, etc.