Plano lenses, also known as zero-power lenses or plano-convex lenses, refer to optical lenses that have no corrective spherical power. In everyday language, the term "plano" is derived from the Latin word "planus," which means flat or level. In the context of eyeglasses, plano lenses are characterized by their flat shape and the absence of any refractive power, whether positive or negative. This means that they do not help correct vision for nearsightedness (myopia) or farsightedness (hyperopia).
When you receive an eye prescription, the term "plano" or "PL" in the sphere box (SPH) will indicate that you do not need correcting power for your eyes. However, you may still have astigmatism, which is a condition where the eye is not perfectly spherical but shaped more like a football. In such cases, you would see a cylinder (CYL) value indicating the degree of astigmatism, and an axis (AXIS) number representing the orientation of the astigmatism.
Plano lenses are typically made of CR39 lens material, which is a type of polymer resin commonly used in eyeglasses. They are generally thicker than demo lenses, which are meant for display purposes only and do not provide any UV or blue light protection. Plano lenses can be coated with anti-glare and anti-scratch tints to enhance their appearance and functionality.
It's important to note that while plano lenses do not provide any vision correction, they still require proper fitting by an optician to ensure comfort and proper alignment within the frames. If you require correction for vision, you would typically receive a prescription for prescription glasses designed to correct nearsightedness, farsightedness, or astigmatism.
