There may arise some problems when a person tries to wear a pair of traditional bifocal reading glasses, especially for those who switch from reading glasses to bifocals. Conventional reading glasses are actually a type of single vision corrective device. And traditional bifocal reading glasses have then been invented to provide extra vision needs by some patients. But this type of vision corrective instrument is also blamed for certain problems, like image jump and unpleasant lens lines. Over the years of eyewear history, there have always been creative people trying to setting aside all of the current shortcomings and worries. No line bifocal reading glasses have been brought into existence for many years. This is a perfect testimony to historical advancement in the eyewear industry. Compared with reading glasses and traditional bifocal reading glasses, no line bifocals as a later comer have several advantages.

Progressive reading glasses are exactly the formal name of no line bifocal reading glasses. The name of no line bifocals is sometimes called as an obvious indication of one of this device's advantages. The populace in the eyewear industry probably knows that there exists a visible line on a regular bifocal lens. For lots of age-aware users, it is nearly a fashion religion to prevent their eyeglasses from showing their unpleasant age. Progressive reading glasses never bother this group of wearers in this aspect. There equipped no visible line on a progressive lens which actually offers a progressively smooth power transition. With such a design, there is no need to separate two or three powers noticeably using one or two lines.

Another significant advantage granted by no line bifocal reading glasses is the comfort of vision perception. Similar to neither a bifocal lens nor a trifocal lens, a progressive lens incorporates a set of various powers evenly arranged in different parts up and down. This advantage is able to avoid the long existing complaint associated with bifocals and trifocals: image jump. Progressive reading glasses never define boundaries between different parts of the lenses. Vision perception at varying distances will always be smooth and comfortable.

Conclusion: no line bifocal reading glasses have certain advantages over either bifocals or trifocals due to their unique and complex lens design. They have no visible lens lines and stay away from image jump.