Which statement describes blended bifocal seg height?

• A. Raise by 1 mm
• B. No change
• C. Lower by 1 mm
• D. Raise by 2 mm

Answer: (A)

The main idea is how the vertical placement of the reading portion sits in front of the pupil when the eye moves from distance to near. In blended bifocals the transition between zones isn’t a sharp edge, so the effective near portion sits a bit differently on the lens compared with a traditional segmented bifocal. Raising the seg height by about 1 mm helps bring the near zone into better alignment with the visual axis during typical reading posture, making it easier to find the near addition without tilting the head or looking through an awkward part of the lens. Not changing it leaves the near area misaligned; lowering it moves the near zone further from the pupil’s downward gaze; raising it by 2 mm would place the near zone too high and could disrupt comfortable use for distance and intermediate vision.