Frame materials and fitting
Your prescription will determine the frames you are able to purchase. Also, the type of material the lenses will be made of will also determine the type of frame to purchase. A prescription that is high will have greater edge thickness (near sighted people) or centre thickness (long sighted people); with thicker edges a sturdier thicker edged frame may be considered to disguise this edge thickness.
For example, rimless frames work for thinner prescriptions with the correct indexed lens, but a rimless frame will not look as good the higher the prescription is, with the increasing edge thickness showing how high the prescription is, even with high index lenses.
Frames can be made from almost any solid non malleable material; However, there are ‘standard’ materials that most glasses frames are made from…
There several plastics that glasses can be made from such as cellulose acetate and proprionate, Optyl and SPX. Plastics are generally robust materials and can be used to make any shape of frame as it can be easily moulded into shape before it hardens.
Many metals and metal alloys have been employed in the manufacture of glasses frames, including crude steel, stainless steel, gold and titanium. Metals have been used to make strong, flexible and light-weight frames, with the exception of gold which is too soft. Most metal frame contain more than one metal as well as other materials; the base metal that provide the structure for the frame, plating – sometimes many different layers and a lacquer coating.
When purchasing your frames, you also want to keep in mind any allergies you may have to metals or plastic. Whether you are purchasing online or in a store, find out what the frames are made of to ensure that you do not have an allergic reaction. You will be wearing them all the time, so if you have known allergies to different materials, check first to make sure there is nothing in the frames that will affect you.
When choosing the frames, make sure they are comfortable on your face. A frame may be the right shape and color, but will feel uncomfortable for one reason or another. Choose a frame that does not slide down your nose or are too tight behind the ears. If you are in store make sure to have the frames adjusted to fit your face properly. If purchasing online, this is difficult to do as trying to do it yourself without the proper tools and know how can lead to damage to your brand new frame.