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Glossary of Eye Definitions and Glasses Terms
Want to discover all things eyewear? Find out more about your eyeglasses and sunglasses, word by word.
BackGlasses Sphere
The sphere eye prescription (SPH) refers to the power of the lens needed to focus light correctly onto the retina. A negative value (-) for the sphere in eye prescriptions indicates nearsightedness, while a positive glasses prescription sphere value (+) indicates the power needed to correct for farsightedness. The sphere (SPH) prescription meaning implies that the correction to properly focus light is the same across all meridians of the eye.
