The distance from the MRP to the center of a bifocal seg is called what?

• A. Inset
• B. Seg Inset
• C. Total Inset
• D. Near PD

Answer: (B)

The distance from the main reference point to the center of the bifocal segment is the segment inset. This measurement sets how far the near portion sits relative to the lens’s reference point, so the wearer can look through the center of the reading segment when viewing through the lower part of the lens. Getting this inset right ensures the reading area aligns with the wearer’s line of sight during close work.

In general terms, just “inset” can be vague, and “total inset” isn’t a standard designation for this measurement. “Near PD” is a separate metric describing the pupillary distance at near work, not the position of the bifocal segment relative to the main reference point.