If you already own a pair of glasses, you'll find numbers engraved on the inside of the eyewear temple. These numbers indicate the following:
LENSWIDTH (A)—
BRIDGEWIDTH (DBL)—
TEMPLELENGTH—
LENSHEIGHT (B)—
The first number is the lens width followed by the bridge width. The third number represents the temple length, or the measurement of the arms of your frame. In some cases there may be a fourth number that indicates the lens height. Measurements in mm.
