When some one wants to group the huge variety of eyeglasses in the market, there are many ways to achieve such a goal. The classification of eyeglasses can be based on factors including frame style, frame material, frame size, lens power, lens material, lens color and so forth. In addition, there are many types of glasses which have combined features, such as prescription sunglasses, prescription goggles, bifocal sunglasses etc. Besides all these possible approaches to eyeglass classification, there is still another basic option. With close evaluation, it is easy to find that eyewear frames produced by different manufacturers may have different structures. While regular spectacles are made with a common frame structure, some ones are special and less widely seen. In most cases, the frame of a pair of regular eyeglasses is composed of a lens frame, two temples and two nose pads. However, this is not all the information of eyeglass structure.
The most obvious difference in special eyewear frames is the bridge. Some people may think that all types of eyeglass frames are connected by a single bridge in the middle of the lens frame. The fact is that this is only the commonest design of bridge, rather than the sole one. While frames with a single bridge are classic and concise, frames with more than one bridge are sometimes favored by individuals who have particularly tastes. In detail, a second design of eyeglass frame is to use two thin bridges to connect the lens frame. These two bridges are nearly in parallel. What’s more particular, there are even eyeglass frames equipped with three bridges. In some instances, it is called a triple bridge. In the third design, the longest bridge usually touches the upper edges of the lens frame. And this extremely long bridge is always designed to be thicker than the other two. Some people may wonder that which brand or brands are providing those outstanding designs of eyeglass frame. In fact, a good example is Aviator, which manufacturers all of these three designs stated in this paragraph. In some cases, the latter two styles look more classic and formal.
Variations of eyeglass frame structure can still be resulted from nose pads. Nowadays, it is quite hard to determine which type of nose pad design is more popular, integrated one or flexible one. While flexible nose pads can be replaced when they become yellowish, integrated ones can only be discarded along with the whole frame. Such a selection depends highly on personal preference.