Vision prescription explainer (SPH, CYL)
SPH: spherical correction. CYL: cylindrical (astigmatism). AXIS: orientation.
⚠ Educational estimates only — not medical advice. Consult a healthcare professional.
About this tool
Vision prescription explainer (SPH, CYL) is a single-purpose utility on instant.tw, a free toolbox of calculators, converters, generators, and quick lookups. Everything works in your browser — nothing is uploaded, nothing is stored on a server unless explicitly noted.
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