what is sph in glasses

SPH stands for Sphere and is an abbreviation you will see on all eyeglass prescriptions. It describes the amount of lens measured in diopters needed for good vision. The term means that the correction for your sight is spherical. If you are shortsighted, the number under the abbreviation will include a (-) sign. The number will have a (+) sign if you are long-sighted. If your prescription has the word Plano, PI, or an infinity sign, it means that you do not have distance problems. You may, however, have astigmatism. SPH is used in bifocal glasses, reading glasses, or varifocal glasses.