Which of the following is NOT a function of aspheric GP contact lenses?

• A. Improved alignment between the cornea and CL
• B. Better centration
• C. Decrease the magnitude of spherical aberrations
• D. Primarily used for Spherical RGPs

Answer: (D)

Aspheric gas-permeable lenses are designed to better match the natural shape of the cornea and to optimize optics across the pupil. By having a back surface that changes curvature gradually rather than staying constant, they improve how the lens sits on the eye and how light is guided through it.

This means they often provide more even contact across the corneal surface, leading to improved alignment between the cornea and the lens. That better fit also contributes to steadier, more centered lens placement, or centration, especially during eye movements.

In optical terms, the gradual change in curvature helps reduce spherical aberration because the lens distributes power more evenly from the center toward the periphery, improving image quality for many pupil sizes.

The statement about being primarily used for spherical RGPs isn’t a function of aspheric GP lenses. These designs are used across a range of corneal shapes, including irregular corneas, and are not limited to spherical rigid lenses.