With a constant base curve and a larger diameter, the sagittal height is

With a constant base curve and a larger diameter, the sagittal height is

• A. Smaller
• B. Ideal
• C. Larger
• D. Unknown

Answer: (C)

Sagittal height is the amount the lens sits up over the cornea. For a fixed base curve, increasing the lens diameter means the lens must cover a wider arc. With the same curvature, a larger arc length raises the posterior surface more, so the sagittal height increases. So the sagittal height is larger. The other options don’t fit because a smaller diameter would reduce sag, “unknown” isn’t correct given the geometric relationship, and “ideal” isn’t a defined outcome of this geometric change.

Sagittal height is the amount the lens sits up over the cornea. For a fixed base curve, increasing the lens diameter means the lens must cover a wider arc. With the same curvature, a larger arc length raises the posterior surface more, so the sagittal height increases. So the sagittal height is larger. The other options don’t fit because a smaller diameter would reduce sag, “unknown” isn’t correct given the geometric relationship, and “ideal” isn’t a defined outcome of this geometric change.