For children who need bifocals, where should the segment line be?

• A. Bisecting the pupil
• B. At the lower lid margin
• C. At the center of the pupil
• D. At the upper lid margin

Answer: (A)

When fitting bifocals for children, the most stable way to share the lens between distance and near tasks is to align the segment with the eye’s central line of sight. Placing the segment line so that it passes through the pupil center keeps the near portion in the visual axis as the child looks straight ahead and then down to read. This central alignment helps the child switch smoothly between looking at distant objects and reading material without having to strain or tilt the head awkwardly.

If the line were placed too high, the child would end up looking through the wrong part of the lens for near work, reducing clarity and causing eye strain. If it were placed too low, the near portion wouldn’t align well with the pupil during typical downward gaze, also producing blur or diplopia. By bisecting the pupil, the reading segment is consistently accessible across the range of natural eye movements, supporting comfortable, reliable reading performance.