Nothing is perfect. We all know this. So whatever we want to know, we have to find their advantages and their disadvantages. What are the advantages and disadvantages of plastic frame bifocal reading glasses?
Advantages:
When we get a pair of plastic frame bifocal reading glasses, there are several advantages that are available. Nearsightedness as a form of refractive error is beyond the capability of regular reading glasses which do not have corresponding power. This makes the magic function of bifocal reading glasses exceptionally notable. In addition to presbyopia correction, plastic frame bifocal reading glasses come with also nearsightedness correction. Prescription lenses equipped in bifocal frames are made with more than one lens power. To be precisely, a bifocal lens has both a plus power and a minus power. Two different parts of a single lens incorporate different powers and thus are able to provide respective forms of vision correction.
The second aspect of advantages of plastic frame bifocal reading glasses is associated with the frame material. Like any other type of spectacles, bifocal reading glasses mean mostly the function of the lenses. They never exert extra requirements on any one of factors of the frame, like frame material, style, color and so forth. So, it is actually feasible to get bifocal reading glasses with any form of frames. But choosing plastic frame bifocal reading glasses will bring certain benefits. It is obvious that plastic frames are more lightweight than their metal counterparts. This is actually the most noticeable advantage while considering frame material. In addition, plastic frame equipped in bifocal reading glasses may help bring down the total price.
The another aspect is clear vision provision. As widely known by the public, bifocal reading glasses provide more help than regular reading glasses. Those conventional reading glasses can only offer clear vision for people who have presbyopia within the near vision zone. In other words, a pair of ordinary reading glasses is designed to provide vision correction on close up objects. The things that are beyond the near vision range are out of the control by a single pair of reading spectacles. One fact associated with most of the presbyopic elder individuals is that they still suffer from nearsightedness which formed probably in their childhood or at a young age.
Disadvantages:
A functional shortcoming of plastic frame bifocal reading glasses is visual distortion. In some instances, new users of bifocal reading glasses need a few days to make an adaption. In serious cases, even headaches and dizziness will be caused. For certain individuals, these reactions even persist for a long time. In fact, these symptoms are caused by the two separated powers in a single lens. A power for nearsightedness and the other one for presbyopia are strictly and suddenly separated using the center line described above. Such an obvious separation or jump will cause some people to experience visual discomfort. In fact, another functional shortcoming is that bifocal reading glasses can not deal with computer tasks professionally. This factor can be resolved by trifocal glasses. All these mentioned shortcomings are equally true in plastic frame reading glasses.
A superficial problem associated with plastic frame bifocal reading glasses is that there is a visible line usually sitting in the center of the lens horizontally. Even the newly developed designs including the D-segment have still visible line or lines for power separation. What is the concern? In an obvious way, these visible lines on the lenses are always telling other individuals that the wearer need reading glasses, which is resulted from presbyopia. This condition is always associated with aging, so that reading glasses are sometimes considered as the symbol of an old age. For most individuals who are still in their middle ages, such an obvious expression caused by visible lines is really unwanted. In addition, these visible lines will surely compromise the wearer’s charming look. From this viewing point, bifocal reading glasses are quite similar to trifocal ones.
You have to get a general, but complete understanding of plastic frame bifocal reading glasses before chooseing them.
