Understanding Frame Measurements

In eyewear, measurements help ensure the frame fits both your face and your lenses properly.

Icon of glasses with measurement labeled 'a' indicating the width of the right lens.

A (Eye Size)

is the width of one lens at its widest horizontal point. This affects how the frame sits across your face and influences overall proportion and lens thickness.

Icon of eyeglasses with a double arrow indicating width measurement, labeled as 'dbl'.

DBL (Distance Between Lenses)

is the space between the two lenses, measured at the bridge. It plays an important role in comfort and proper optical alignment.

Icon of eyeglasses with a measurement labeled 'b' indicating the height of one lens, set against a dark blue circular background.

B (Lens Height)

is the vertical height of the lens at its tallest point. This measurement is especially important for progressive lenses and overall lens design.

Graphic of eyeglasses with the word "ed" inside the right lens.

ED (Effective Diameter)

is the longest diagonal measurement of the lens. It helps determine lens blank sizing and is important when calculating lens thickness and edge appearance.

Together, these measurements ensure your eyewear is balanced, comfortable, and optically precise.