"Eyewear" is a term that describes glasses, sunglasses, lenses and anything else that is used to cover the eyes either for protection, better vision, fashion, or a combination of all three. Eyewear is normally dispensed at a glasses store or a sport shop (in the case of sunglasses). Now you can buy the same designer glasses with the same high-quality prescription lenses at Eyeglasses.com, just like you can in eyeglasses stores. Nowadays, many people are buying prescription sunglasses and eyeglasses online, in order to save money and get a bigger selection.
Determining eyewear quality is quite difficult, even for an industry professional. Designer glasses are all made with good quality, which is why you should buy designer eyewear online, to get the same high quality as you would get from an eyeglass store, but with much more selection and much lower prices. The most reliable determinant of prescription eyewear quality is the feel of them in your hand. Do they rattle? Do they feel stiff and solid? When you exercise the hinges do they move smoothly and with the same friction throughout the bend? A better quality eyeglasses frame has a higher level of machined perfection, so that the better quality parts fit together well.
The world's leading eyewear makers all make good quality eyewear. You will find these in eyeglass stores at more than double the prices of Eyeglasses.com. This would include Luxottica (Ray Ban eyewear, Oakley eyewear, Versace eyewear, Polo eyewear, and many others), Safilo Group (Carrera eyewear, Kate Spade eyewear, Hugo Boss eyewear, and many others), Kering Group (Gucci eyewear), Marcolin Group (Tom Ford, Kenneth Cole, Guess eye wear and others), and Marchon Eyewear (Calvin Klein, Salvatore Ferragamo, DKNY and others). There are many other quality makers of eyewear, including Aspex eyewear, and Revolution eyewear, which are the leaders in clip on sunglasses.
Consider glass frame design model A: using German hinges and Italian Mazzucchelli zyl, which is considered the best, results in an excellent quality European glasses frame. Yet this same frame design model A could instead use Mazzucchelli zyl from China (same company, different factory), Chinese hinges, and be assembled in a Chinese factory. The Chinese frame would be very difficult to differentiate from the original, except that it would be designated Made in China. Now, let's say that this same frame model A used Mazzucchelli zyl from China, and Chinese hinges, but was assembled in Italy, it would be called Italian eyewear, Made in Italy. Most European eyewear nowadays (except for a few high end brands) that is made in Europe is made mostly of Chinese components. You can understand why determining glasses frame quality is so difficult.
Nowadays, about 90% of all eyeglasses are made in China. All of the major Italian glasses frame companies have moved the majority of their production to China. Many of the eyeglasses that are made in China are then shipped to Europe where a minimal amount of assembly or finishing work is done so that the glasses frames can receive the Made in Europe designation. There are some designers, like Lafont, and Silhouette and a few others that make their glasses frames completely in Europe. Brands like Armani, Gucci, and other big fashion houses are mostly made in China, and then finished in Europe. This is not to say that China eyewear is of inferior quality. China has been making eyewear for many years and the quality is quite good.
Hinges are a small but very important component in the overall quality of your glasses frame. If the hinge is not mounted on the frame properly, it will disengage which leads to a very difficult (or impossible) repair job. Low quality hinges will wear out, the screw will pop out and get lost, and they will wear quickly leading to rattling or sloppy action. Good quality hinges have a smooth and consistent action that does not wear over time, with friction that is consistent throughout the entire range of motion.
Eyewear dates back to Roman times. According to Wikipedia, one of the earliest evidences of the use of prescription eyewear is found in the 1352 portrait painted by the Italian painter, Tommaso da Modena, of the Dominican Cardinal Hugh of Saint-Cher who was a renowned biblical scholar. Another example, this time an apostle wearing a type of reading glasses, is found in the central panel from an altarpiece painted by Conrad von Soest in 1403, Bad Wildungen, Germany. Surprisingly, the basic design of glasses has not changed in over 2000 years - a frame, sitting mostly on the ears and nose (there are exceptions), positions lenses in front of the eyes so the wearer can see better.
Zyl is a short name for the material cellulose acetate, which is made of wood flakes, cottonseed fibers, stabilizers and plasticizers. Zyl is the most common plastic frame material because it can assume a large array of colors, textures and patterns. Temples and frame fronts can be cut from blocks of zyl extruded as a sheet of block acetate. Or, granular zyl can be liquefied and then injection molded. Block-cut zyl is stronger and more stable, while injection molded zyl is less stable and less expensive. With daily use in warm temperatures, zyl can shift and lose its form. Sometimes metal cores are added in the temples in order to strengthen and stabilize the frame.
Monel is composed of about two-thirds nickel and one-third copper. This highly ductile alloy can be hammered into a variety of different shapes without losing strength. It resists stress well is often use to stabilize frame bridges and endpieces. Monel colors well, is corrosion resistant, and durable. If you have an allergy to some metals, it is usually the nickel in the metal that causes allergic reactions.
Titanium is extremely lightweight and will not rust, making it a very popular and relatively new material for eyewear frames. Titanium's strength allows it to be made thin, but it is hard to solder or weld and is expensive. Titanium is a more expensive metal composite used in eye glasses frames known for its beneficial qualities of strength, lightness, and flexibility. However, titanium is very difficult to color so titanium frames usually come in a very restricted range of eyeglasses frames colors. Eyeglass frames that are 100% titanium are also a hypo-allergenic--they do not contain any nickel which causes allergic reactions in some people.
Stainless steel is comprised mostly of iron, with a mixture of nickel, manganese, and chromium. Stainless steel is highly lustrous, and makes a good thin and sturdy eye glasses frames with strong corrosion resistance. Although it is hard to make eye glasses frames with stainless steel due to soldering and welding difficulties, stainless steel temples are especially springy.
Nylon is virtually unbreakable, so it is often chosen for sports and safety applications. Nylon is lightweight and flexible, but can only accept opaque colors. Nylon is a soft material, so it scratches easily, and is used in many low-cost, low-quality eyeglass frame and sunglasses applications.
Sometimes called "Alpaca" or "German Silver", nickel silver is rigid compared to other more malleable metals. Nickel silvers contain more than 50% copper, 25% nickel, and the rest zinc (no silver at all). Copper adds pliability, zinc adds strength, and nickel gives it its namesake color, a whitish appearance, because when the nickel content exceeds 12% the copper color no longer shows through. Although the metal is lustrous, its brittleness makes it a poor choice for slender frame fronts and nose pads. Thus, it is better designed for use in hinges, endpieces, bridges and ornamental trims, as well as an inner core for temples.
Flexon is a trade name for one company's flexible eyeglasses frames material. Flexible eyeglass frames are available in many compositions, but the goal is always the same. This kind of material is used in eyeglass frames in order to reduce breakage. It is normally found in the shaft of the temple and in the bridge, and it allows these areas to endure tremendous twisting without breakage or permanent distortion of the frames shape.