While rimless eyeglasses look more fashionable, their parts have approximately a 35% higher chance of getting damaged than their rimmed counterparts. So much so, that on an average, the lenses on rimless glasses have to be replaced three times each year.Eyeglasses are frames that hold lenses in front of the eyes of an individual. Usually used for correcting vision problems, some of them are also used as style or fashion statements. Other safety glasses protect the eyes from unsuitable light or airborne debris. One can even find glasses, which show objects in a different perspective, such as 3D imaging.
As such, the parts of eyeglasses will also differ in appearance as well as in technical specifications. For the purpose of this article, we will focus specifically on the parts of spectacles and sunglasses, that are used in everyday life by a common man.
Parts of Eyeglasses/Spectacles
Made from glass, plastic, or polycarbonate, lenses are parts of the eyeglasses that are meant to correct the vision of the wearer, and protect the eyes from harmful UV rays and flying debris. Vision-correcting lenses are either convex or concave, which correct farsightedness and nearsightedness respectively. These lenses come in either single-vision or multi-focal varieties, which work on either single or multiple vision problems.
Earlier, glass was the predominant material used to make lenses. Nowadays however, plastic is the most popular option due its clarity and low expenses. Its disadvantage is that plastic can get scratched and damaged. A better option is polycarbonate lenses which are shatter-resistant and very lightweight.
The largest part of the eyeglasses, the frame front/chassis holds the lenses in place, and is usually made of rims of plastic or metal. Plastic chassis is made of blended nylon or cellulose acetate. Metal frames on the other hand are usually made from a combination of various metals titanium, steel, aluminum, etc., called monel. The frame front can usually be divided into the lens rims, the bridge, and the end pieces that are fixed with hinges to the frame temples.
Frame temples are the long arms which are fixed through hinges and screws to the frame front. Most temples are straight with a marginal bent to hold the glasses on the ears, while you can also find some which bend behind and under the ears, to get a better anchor. Depending on the degree of bending and material, the temples come in four types: comfort-cable, riding bow, paddle, and spring-hinged. The temples usually end with tips that are either made of soft plastic or rubber, which allows a comfortable fit without chafing on the skin of the ears.
Nose pads made of plastic or rubber are fixed to the internal rims of the frame front, through metal or plastic pad arms. They work to keep the glasses positioned by taking the support of the nose, without compromising on comfort.
The bridge is the metal or plastic part that keeps the rims of the two lenses together. It is either a fixed eyeglass frame part or a removable one. In older versions of eyeglasses, the bridge would rest on the nose and provide support for the glasses. However, this function has now been taken over by nose pads. The bridge of the glasses are available in 4 types: saddle, double, keyhole, and adjustable. While saddle and double bridges are best for heavy glasses, while keyhole varieties are best for people with small noses. Adjustable bridges are the best, for those users who want a flexible fitting. Sometimes, the glasses may also have an extra metal or plastic bar above the bridge, which connects the two rims, and gives additional support to the frame.
The parts of sunglasses are the same as mentioned above, the only difference being in the lenses, which do not work to correct vision, but are meant to enhance the appearance of the wearer, with some exceptions which protect the eyes from UV rays of the sun. The parts of rimless eyeglasses do not include any rims/eye wires. Instead the bridge and temples are directly fixed to the lenses. The above guide should help you when making repairs or replacing the parts of your spectacles or goggles.