The size of progressive glasses frames

Progressive eyeglasses differ from traditional reading glasses, bifocals or trifocals in lens design. While those three types provide one to three lens powers in a single lens, progressive spectacles incorporate a set of different powers in their lenses. The majority of presbyopic patients may have known this functional difference between other forms of multifocal reading glasses and progressive glasses. However, there may be fewer people know that progressive glasses frames can also differ from the frames of other reading glasses. This saying is well founded. In fact, even progressive glasses users want to wear attractive frames with fashionable styles. And progressive eyeglass frames manufacturers should consider all traditional factors that are involved in regular types of glasses.

Frame size is the most critical factor that may differentiate progressive glasses from other forms of reading glasses. First let’s discuss the frame size of regular reading glasses, bifocal and trifocals. Traditional reading glasses all take use of single vision lenses, so that lens design will not impose extra requirement on frame size. When it comes to bifocal lenses or trifocal lenses, there is more than one power in a single lens. Some people may get worried that the frame should be large enough to host large lenses which will provide enough visual field at each part. In fact, two or three focal points can be easily arranged in a small frame, with modern lens technologies.

The task is slightly harder when opticians try to insert progressive lenses into a small frame. The reason is that a progressive lens comes with a gradient of increasing powers. If the frame is too small, the reading portion of the lens may become particularly narrow and cause uncomfortable reading experience. This is because progressive lenses should be cut to a size that is compatible with the small frame. Without the availability of “short corridor” progressive lenses, progressive glasses frames have to be relative large if the wearer expects normal reading aid. However, modern lens technologies have made it possible to take use of “short corridor” progressive lenses and specialty lenses with customized reading or intermediate portion.

C: Progressive glasses frames were at a time larger than bifocal frames or trifocal frames. The development of “short corridor” progressive lenses and customized lenses makes presbyopic individuals to enjoy those small frames.