How to read a Spectacles Prescription

Ever wondered what are all those numbers on your glasses prescription (or "script")? Here's how to decipher it!


SPH

CYL

AXIS

Right

-1.25

-0.50

180

Left

-1.50

-0.75

005

ADD

R / L +1.00

PD

R 31 / L 31

Type of Lenses

Progressives

This is what a typical prescription would look like.


We have a SPH, CYL, and AXIS value for both the Right and Left eyes.


SPH refers to the spherical component, it is either myopia (negative number) or hyperopia (positive number).


CYL refers to the cylindrical component, and it is your astigmatism; in Singapore this will be a negative number (e.g. -0.50), but in some parts of the world, it is given as a positive number (e.g. +0.50).


AXIS refers to the angle of the CYL, simply put, it is the direction of your astigmatism. It can range from 001 to 180, and a higher number does not mean it is worse - it is just like a bearing on a compass.


ADD refers to the addition, which is the power required to aid reading in people with presbyopia (usually those above 40 years old when reading starts getting difficult).


PD refers to the pupillary distance, which is the distance between the pupils of your eyes. This can be given as one number (e.g. 62mm) or as a right and left component (R31/L31)


Some prescriptions will state the type of lenses if they have been prescribed or are suggested to be prescribed. If you are over 40 years old and presbyopic (have presbyopia), single vision corrects for a single use - Far, Intermediate, or Near use. Office lenses correct for Intermediate and Near, while Progressives correct for Far, Intermediate, and Near vision.



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