When is the MRP located at the lens optical center?

The most accurate scenario regarding the location of the Minimum Refraction Power (MRP) at the lens optical center is when no prism is prescribed. In this situation, the optical center aligns with the MRP, which is crucial for ensuring that light entering the lens is not distorted and the wearer experiences minimal optical degradation.

When prism is prescribed, the optical center shifts away from the MRP to accommodate the desired visual effect, which means the MRP cannot simultaneously be at the optical center. Similarly, while high-index lenses offer advantages like thinner profiles, their characteristics do not inherently impact the relationship between the MRP and the optical center unless prism corrections are involved. Lastly, the concept of a lens being "cut perfect" does not necessarily influence the MRP’s position relative to the optical center.

Understanding this alignment is essential because misalignment can lead to visual discomfort and inefficiencies in vision correction.