There are two straightforward ways to find measurements for your frame size. The first is to use a pair of old eyeglasses that you can use for comparison. If they fit well, copy down the measurements; if they could use some adjustment, think about which specifications need to change for a better fit.
Another way to determine your ideal frame size is to take the measurements yourself. In much the same way as taking measurements for clothing, measure your face to determine what size of frame you need.
While standing in front of a mirror, use a ruler to determine your ideal specifications for these important frame measurements (all in millimetres):
● Frame width: The furthest two points across the horizontal width of the frame including the parts that stick out
● Lens height: The vertical height of a lens at its tallest point; needs to exceed 30mm for bifocal/progressive prescriptions.
● Lens width: The horizontal width of the lenses at its widest point. Also known as “eye size,” lens width comes in three sizes (small: 50mm or less, medium: 51-54mm, and large: 55mm+).
● Bridge size: The part of the glasses that goes across the bridge of the nose, representing the distance between lenses; measured horizontally from the inner edge of one lens to the other.
● Temple length: The distance from the tip of the arms (after the bend in the ear) to the hinge of the glasses; because of the bend, it may be easier to do this measurement in two parts.
Some important things to keep in mind for each of these measurements:
● A good rule of thumb to use for frame width is to find a frame that is slightly wider than your face. Ideally, there should be no more than a finger's width of room between the temple and face.
● Be picky with your selection. Choose too narrow a frame, and it will make your face look wider; choose too wide, and it will make your face look narrow.
● Ideally, each of your eyes should be in the centre of each lens; if your frames are too wide, your eyes will appear too close together, while narrow frames will give your eyes a wide-set look.