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How to Read a Vision Prescription | Bard Optical

How to Read a Vision Prescription

Woman reading her vision prescription on her phone

So, you’ve just received your eye prescription from your doctor and you’re trying to understand all the foreign abbreviations and numbers.

This task can feel impossible, especially if this is your first prescription.

Not to fear, however! Let’s break down together how to quickly and accurately read each part of your prescription:

Reading Your Prescription

The first thing you might notice when looking at your prescription is two abbreviations, OS and OD.

These are Latin abbreviations, with OS standing for “oculus sinister”, or ‘left eye, and OD standing for “oculus dextrus”, or ‘right eye’.

These markings only serve to differentiate which numbers refer to your right eye and which refer to your left.

The numbers on your prescription can be tricky to understand, but generally speaking, the higher the number, the more correction your eyes need.

Often, those numbers will be accompanied by either a plus (+) or a minus (-). The function of these symbols is very simple!

The plus (+) means you are farsighted, while the minus (-) means you are near-sighted.

Understanding how these numbers and symbols work together is another matter.

The numbers shown on your prescription represent a diopter, a unit of measurement equal to the refractive power of a particular lens, such as your eyes.

This means that if you see the number 2.00 on your prescription with the plus (+) symbol in front of it, like +2.00,  this means you have 2.00 diopters of farsightedness.


Besides the plus and minus symbols, there are also a variety of other symbols that can appear on your prescriptions.

For instance, ‘PD’ is the label for your “pupillary distance”, or the distance between your eyes from pupil to pupil.

‘CYL’ will show you how astigmatism you have.

‘PRISM’ will appear if you have a muscle imbalance within your eye.

‘ADD’ is a value used for reading glasses and bifocals to indicate the power of the lenses.

‘SPH’ and ‘PWR’ refer to the main strength of your eyeglass prescription.

A doctor may write ‘NV or NVO’, which stands for near vision or near vision only. This is used to prescribe reading glasses only in some cases of farsightedness.

‘DV or DVO’ is the opposite of NV, standing for distance vision or distance vision only.

‘AXIS’ is used for astigmatism correction. It is used to reference the position of the cylinder that corrects astigmatism and comes in increments of 1 between 1 and 180. The sharper the angle of the cylinder, the higher the Axis number, since the number is directly correlated to the angle.

There are many more symbols that can be used on a case-by-case basis, but these are considered to be the most common.

In truth, your eye prescription is not impossible to read, it just takes time and practice to learn the culture of eye care as it pertains to you.

If your eye prescription seems like a foreign language to you, talk to your doctor! They will always be willing to help you understand how the numbers relate to your eyesight and will help you on your way to reading prescriptions like a pro!

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