The correct fit
The size of your frames can affect the look of the glasses on your face and how comfortable they are to wear:
- The top edge of the frames should be no higher than the line of your eyebrows.
- The bridge design and position is the key to a comfortable fit.
- The lower edge of the frames should not sit on your cheeks, even when you smile, so that they don't rub or irritate.
- The size should be in proportion to your face - if you have a small face, don't choose large glasses.
- The width of the frames should not be wider than the overall width of your face at the temples.
If you look on the inside of the arm of your glasses you find will something that looks like: 52  18 135.
This is information on the size of your glasses: the lens diameter, the bridge width and the arm length, all measured in millimetres.
The lens diameter is the width of the lens (in mm), measured from the bridge. This can be a matter of personal choice, but is also determined by your frame style.
The bridge width is the gap above your nose between the lenses. It should be comfortable. Too tight, and the glasses could pinch your nose; too loose and the glasses will not be stable on your face.
The arm length is usually one of three standards – 135, 140 or 145mm. The arm should be long enough to sit comfortably over your ears. Glasses with straight arms do not always have this measurement indicated.