On an eye prescription, ‘PL’ typically stands for Plano. This term indicates that no corrective power for sphere (SPH) is required for that eye. In essence, the lens needed is flat or has zero refractive power. For instance, an eye prescription might list “OD: PL,” meaning the right eye requires no spherical correction.
The presence of Plano on an eye prescription is significant as it specifies that the individual’s vision for that eye is already at the desired level without the need for lenses to correct nearsightedness or farsightedness. Historically, eye prescriptions have evolved to precisely communicate the lens characteristics required for optimal vision correction, with terms like Plano providing clarity for both the optician and the patient. Recognizing this term ensures that only the necessary corrective measures are implemented, preventing over-correction.