On the back of spectacle frames, what do the figures such as 46 x 22 represent?

The figures such as 46 x 22 found on the back of spectacle frames represent the size of the lenses and the bridge width. The first number, 46, indicates the width of each lens, typically measured in millimeters, while the second number, 22, represents the bridge size - the distance between the lenses across the bridge of the nose. This information is crucial for ensuring a proper fit and comfort for the wearer, as it helps to determine how the glasses will sit on the face and the overall aesthetics of the frame.

Understanding these measurements is essential for opticians and consumers alike, as they influence both the functionality and style of the eyewear. Customers often need to select frames that accommodate their specific measurements for optimal vision correction and comfort, making awareness of these particular dimensions significant in making an informed choice when purchasing glasses.