How to Read an Eyeglass Prescription: SPH, CYL, AXIS and PD Explained

An eyeglass prescription can look like a compact table of abbreviations and numbers. Understanding the basic labels can make online ordering easier, but your prescription should still be interpreted and issued by your eye-care professional.

OD and OS

OD refers to the right eye and OS to the left eye. Some prescriptions may also use OU when referring to both eyes.

SPH: sphere

SPH is the spherical lens power written on the prescription. It may appear with a plus or minus sign. Enter the value exactly as prescribed rather than changing the sign or rounding it.

CYL and AXIS

CYL and AXIS are commonly used together when astigmatism correction is prescribed. If these fields appear on your prescription, copy the values exactly into the corresponding fields during ordering.

PD: pupillary distance

PD is a measurement related to the position of your pupils. It is not the same as the three frame measurements printed inside many eyeglasses. Do not substitute lens width or bridge width for PD.

Our frame measurement guide explains the difference between lens width, bridge width, temple length, and PD.

Near vs. distance single vision

Single vision lenses use one corrective power across the lens. Depending on your prescription and intended use, your eye-care professional may prescribe single vision correction for distance or for near tasks. Select the option that corresponds to the prescription you intend Lucent to fill.

Do not guess at missing prescription information

If a value is unclear, missing, expired, or difficult to read, contact the prescribing eye-care professional before ordering. Lucent's ordering tools are not a substitute for an eye examination or professional interpretation of your prescription.

Choose your frame after checking the practical details

Browse eyeglasses, including rectangular, cat-eye, and titanium styles. Compare the exact frame measurements and available variants before making your selection.

Then compare Lucent lens packages

Lucent Optical currently focuses on single vision lens packages. Review the available lens materials, coatings, pricing, and prescription-range information for your selection rather than assuming every option is appropriate for every prescription.

Use the Lucent single vision lens guide and our prescription glasses buying guide for the next steps.

Shop Lucent Optical eyeglasses.