Which measurement does not affect the fitting of eyewear?

The choice regarding temporal length as not affecting the fitting of eyewear is accurate because temporal length refers to the length of the temples (the arms of the glasses) that extend over the ears. This measurement does not directly impact the overall fit or placement of the lenses in relation to the wearer's eyes. Instead, it primarily influences comfort, especially in how the glasses rest on the wearer's head, but it does not alter the accuracy of lens positioning or vision correction.

In contrast, the other measurements are critical in the fitting process. The box dimensions provide a reference for the overall size of the frame, which is important in ensuring that the lenses fit within the frame appropriately and that the frame aligns correctly with the wearer's facial features. The frame pupillary distance (PD) is a highly significant measurement as it determines how well the optical center of the lenses aligns with the wearer's pupils, which is essential for optimal vision. The B box dimension relates to the height of the lenses within the frame, which affects both fit and vision by ensuring that the lenses are positioned correctly in relation to the wearer's gaze. Therefore, temporal length, while relevant for comfort, does not affect the fundamental fitting and function of eyewear the way the other measurements do.