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One of the most popular multifocal glasses -- Bifocal prescription glasses
With the growth of the age, the ability of the human’s eye vision adjustment will come worse and worse. And many people will have to back up two pairs of glasses respectively for distance and computer or reading use which seems very inconvenience since they have to make glasses switches in different conditions. But with the appearance of prescription multifocal lenses, the above inconvenience has been solved and bifocal prescription glasses are one of the widely used multifocal lenses among the prescription glasses wearers.
There are many kinds of bifocal glasses sold in the current eyeglasses market. For example, if clarified by the structure of the lenses, there are round top bifocal lenses and flat top ones. And if clarified according to the presence of the line in the lens, it includes the lined bifocal glasses and no-line bifocal (which is also called progressive bifocal). One of the most popular prescription bifocal lenses is the FT28 (flat top D-segment which is generally 28 mm wide). Many people choose this kind of lenses for the reason that these D-segment bifocal prescription glasses offer better viewing qualities.
The lenses for bifocal progressive glasses contain two fields of vision which are separated by a visible line. Generally speaking, the lower part of the lenses was used for viewing nearby objects while the upper half for the distance viewing. The reading area is positioned just below the centerline of the lens and it is approximately 25mm wide. The actual height of the reading area for the prescription bifocal glasses will be affected by the height of the lens chosen.
When it comes to the frame material, since special function of the lenses will not require extra requirements on the frame design, prescription bifocal glasses are almost available in all possible options at present, such as plastics, metals, titanium, acetate and even mixed materials. You can also see bifocal prescription glasses frames in nearly all styles including full frame, half-rim and rimless which are the same stylish and fashionable if not better than any prescription glasses frames.
As a suggestion for choosing the frame for bifocal prescription glasses, you’d better choose frames with the higher lens height. Since if you choose a frame with very small lens height for your bifocal prescription glasses, the reading portion of the lens would sometimes reduce a lot which you might not get adapt to and it can even cause headaches and even dizziness. |
