Which design typically has the distance power in the center?

The correct answer is what's known as the Rigid Designs. In these designs, the distance power is generally placed in the center of the lens. This arrangement is important because it allows for clearer vision at distance, which is a critical aspect for many wearers who may be primarily focused on long-range viewing tasks.

Rigid designs, often referring to gas permeable lenses, are known for their ability to maintain their shape on the eye, which contributes to clear and stable visual acuity for distance. This is especially beneficial for individuals who require precise vision at a distance, like those with astigmatism or other refractive errors.

While monovision designs might use differing lens powers in each eye to facilitate both distance and near vision, they do not typically feature distance power centrally. Aspheric designs are known for providing a smoother transition between different powers and have varying curves across the lens. Concentric designs involve rings of differing powers, which do not have a single focal point in the center, making them less suitable for pure distance vision.

In summary, rigid design lenses are specifically structured to prioritize distance vision by placing that power centrally, which differentiates them from other designs that may use varying focal points or configurations.