What does "PL" stand for in eyeglasses prescriptions?

In eyeglasses prescriptions, "PL" stands for "Plano." This term indicates that there is no refractive error in the prescription for that specific measurement, meaning the lens is meant to correct no optical defect. It is typically used to denote that the lens has no spherical power, making it neutral in terms of refractive correction.

The understanding of "plano" is crucial in eyeglass prescriptions, as it helps to identify lenses designed for individuals whose visual acuity does not necessitate correction in that particular axis. For instance, in cases where a prescription includes multiple measurements, a plano designation implies that the vision in that specific meridian is normal or uncorrected.

For context, while "plus" typically refers to lenses that are convex and correct hyperopia, and "presbyopic" pertains to a condition associated with aging that affects near vision, these terms convey different meanings and are not applicable in defining the neutral state of no required vision correction.