Types of Spectacles

Spectacles, more commonly known as eyeglasses, come in a variety of styles and shapes. Eyeglass frames may be sorted into categories based either upon the materials used to create the frames the various styles of frames. Eyeglass styles should suit the shape of the wearer's face and complement the warm or cool tone of the wearer's skin.

Plastic

• Plastic frames offer the wearer a wide variety of colors and styles. All About Vision notes that plastic frames consist of either zyl, cellulose acetate propionate or nylon blends. Zyl stands for zylonite, another name for cellulose acetate. Frames made from zyl offer a lightweight and cost-effective option for wearers. They come in all colors of the rainbow, with some featuring multiple colors in the frames. Cellulose acetate propionate also gives wearers a lightweight option, but are hypoallergenic and more transparent and glossy. Nylon-blend spectacles are preferred by athletes and those who need high-performance frames. Some disadvantages of plastic frames include their being broken easily and their propensity for weakening and fading slightly with sun exposure. Plastic-framed glasses also tend to lack eyepads.

Metal

• Metal-framed spectacles provide a more solid feel than other types and are harder to break. Metal frames come in several different materials. Some of the more common metals include stainless steel, titanium and flexon. The most widely used metal for glasses, according to All About Vision, is monel. Monel mixes several different metals and creates a flexible, corrosion-resistant frame. The majority of metal frames are lightweight and hypoallergenic; monel and aluminum lack the hypoallergenic quality of other metal frames. Metal frames often feature eyepads, which rest against the sides of the wearer's nose to position the glasses comfortably in place.

Other Materials

• While plastic or metal spectacle frames dominate the glasses market, those willing to pay the extra buck can find frames that are one-of-a-kind. Frames may come in gold-plated form, though silver and gold are not usually used alone because of the discomfort and fragility these materials possess. Wooden spectacle frames also feature less flexibility but are more common than gold or silver. Bone, another stiff material, may also be used. Buffalo horn glasses are rare but provide the wearer with a unique sensation; according to All About Vision, the material warms to the wearer's body temperature and feels very different from other glasses.