If a seg height appears too low on a patient, should you increase or decrease the vertex distance?

If a seg height appears too low on a patient, should you increase or decrease the vertex distance?

• A. Decrease the vertex distance
• B. Increase the vertex distance
• C. No change
• D. Switch to a different frame

Answer: (B)

The segment height you see through the lens depends on how far the frame sits from the eye. If the near segment appears too low, moving the frame slightly farther away from the eye (increasing vertex distance) makes the eye’s line of sight intercept a higher portion of the lens, bringing the reading segment up into the correct position. Decreasing vertex distance would pull the segment lower, which wouldn’t fix the issue, and switching frames or making no change won’t address the vertical misalignment.

The segment height you see through the lens depends on how far the frame sits from the eye. If the near segment appears too low, moving the frame slightly farther away from the eye (increasing vertex distance) makes the eye’s line of sight intercept a higher portion of the lens, bringing the reading segment up into the correct position. Decreasing vertex distance would pull the segment lower, which wouldn’t fix the issue, and switching frames or making no change won’t address the vertical misalignment.