As the pantoscopic tilt is increased, what should happen to the distance optical center?

As the pantoscopic tilt of a pair of spectacles is increased, the optical center of the lens position relative to the eye typically lowers. This occurs because increasing the pantoscopic tilt causes the lenses to angle more steeply downwards, thus moving the optical center toward the wearer's cheeks.

In the context of lens design, the optical center is the point on the lens where light is ideally focused, and it is aligned with the wearer’s line of sight for optimal visual clarity. When the tilt is adjusted, the wearer's gaze direction changes, necessitating a corresponding shift in the optical center to maintain effective vision and minimize distortions.

So, in practical application, as the tilt increases, adjusting the height of the optical center downwards ensures that the wearer maintains clear vision through the correct part of the lens. This alignment is crucial for comfort and visual acuity in eyewear.