When using an OC height for aspheric lenses, what should be done concerning the pantoscopic angle?

When dealing with aspheric lenses, maintaining an optimal optical performance is essential, particularly concerning the optical center (OC) height and the pantoscopic angle. Aspheric lenses are designed to provide a more uniform optical quality across the lens surface, which can be sensitive to the positioning of the lens relative to the eye.

Using no pantoscopic angle—the orientation in which the bottom of the frame tilts slightly forward—means that the lens remains vertically aligned with respect to the wearer's line of sight. Aspheric lenses typically benefit from being positioned to minimize distortion, especially in multifocal designs. If the pantoscopic angle is absent, it ensures that the optical center is correctly aligned with the pupil, preserving the intended design advantages of the aspheric surface.

In practice, this alignment is crucial because any deviation in tilt may introduce unwanted aberrations or distortions, which aspheric lenses are specifically engineered to reduce. Therefore, regarding the application of pantoscopic angle in the use of aspheric lenses, avoiding it altogether aids in achieving the best visual outcomes by keeping the optical center optimally directed toward the line of sight.