How to Read Your Prescription

Your glasses prescription contains a few numbers and abbreviations that tell the optician how to make lenses that correct your vision.

Below is a simple explanation of the most common terms.

SPH indicates the strength of the lens needed to correct short-sightedness or long-sightedness.

A minus (-) value means you are short-sighted.

A plus (+) value means you are long-sighted.

CYL shows the amount of astigmatism correction needed in your lens.

Astigmatism occurs when the eye is not perfectly round, which can cause blurred vision.

Axis works together with the CYL value.

It indicates the angle of the astigmatism correction in your lens and is measured between 1 and 180 degrees.

ADD is used for reading or multifocal lenses.

It shows the additional magnification needed for

close-up vision.

PD is the distance between the centres of your pupils.

This measurement ensures your lenses are positioned correctly in the frame for clear vision.

If your prescription does not include PD, you can measure it yourself using our PD Measurement Guide.