What is the recommended OC height placement if B measurement is less than the OC height requested?

When determining the optimal placement for the optical center (OC) height in relation to measurements of the individual, it is important to consider how these placements affect the optical performance of the lenses. If the "B measurement," which refers to the vertical dimension of the frame at its widest point, is less than the requested OC height, placing the OC above the geometric center of the lens becomes the recommended approach.

This placement allows for more effective alignment of the optical center with the wearer's line of sight, particularly in scenarios where the frames do not provide sufficient height to accommodate the requested OC without compromising visual clarity and comfort. As the OC height is important for visual acuity, placing it above the geometric center ensures that the optical properties of the lens will still serve the intended visual needs while remaining within the frame's physical constraints.

Positioning the OC too low (like at the geometric center or below) is likely to result in suboptimal visual performance, causing the user to have to look through a portion of the lens that is not optimally calibrated for their vision correction needs. Therefore, placing it above the geometric center is emphasized as the best practice in this context.