Which statement about adjusting sagittal height for a steep GP lens is correct?

Which statement about adjusting sagittal height for a steep GP lens is correct?

• A. Increasing sagittal height creates a flatter fit.
• B. Increasing sagittal height creates a steeper fit.
• C. Decreasing sagittal height creates a flatter fit.
• D. Sagittal height does not affect fit.

Answer: (C)

Sagittal height is the vertical distance from the lens’ posterior surface to the corneal apex. It determines how much the lens vaults over the cornea and how the edge sits on the tear film and sclera. When you increase sagittal height, the lens vault becomes higher and the fit takes on a steeper character with less overall movement. Conversely, decreasing sagittal height lowers the posterior vault, which reduces steepness and produces a flatter fit with more tear-lens interaction and movement. So to achieve a flatter fit for a GP lens, you would decrease sagittal height. If you needed a steeper fit, you would increase sagittal height.

Sagittal height is the vertical distance from the lens’ posterior surface to the corneal apex. It determines how much the lens vaults over the cornea and how the edge sits on the tear film and sclera. When you increase sagittal height, the lens vault becomes higher and the fit takes on a steeper character with less overall movement. Conversely, decreasing sagittal height lowers the posterior vault, which reduces steepness and produces a flatter fit with more tear-lens interaction and movement. So to achieve a flatter fit for a GP lens, you would decrease sagittal height. If you needed a steeper fit, you would increase sagittal height.