How to Read an Eyeglass Prescription

Navigating an eyeglass prescription might seem tricky at first, but with some guidance, it’s easy to understand what each part means. Whether you’ve just received your prescription or are curious about how to read an eyeglass prescription, we’ve broken it down for you.
Understanding the basics of your prescription
An eyeglass prescription is made up of a few key numbers that describe the specifics of your vision needs. These numbers will typically be written as follows

This stands for "oculus dexter," the medical term for your right eye.

This stands for "oculus sinister," referring to your left eye.
Sometimes, you may see OU (both eyes), which refers to your overall prescription.

Now, let’s get into the numbers themselves. Here’s what each of them means:

This number tells you the strength of the prescription. It will be a positive (+) or negative (-) number:

A negative number means you’re nearsighted (myopic), so you’ll need glasses to see things at a distance.

A positive number indicates you’re farsighted (hyperopic), meaning you need glasses to see things up close.

This value indicates astigmatism, which happens when your cornea is irregularly shaped. The cylinder number will also have a positive or negative value. If there’s no cylinder measurement, you don’t have astigmatism.

The axis refers to the orientation of the astigmatism, measured in degrees from 1 to 180. This number will only appear if your prescription has a cylinder value.

Another important piece of information is your pupillary distance (PD). This measures the distance between the centers of your pupils, which helps ensure your lenses are correctly aligned. Your optometrist may include this measurement in your prescription, or you may need to measure it yourself (or ask your optometrist for it).

For single vision, a typical prescription might look like the example above:
This would indicate a prescription for nearsightedness, where the same correction applies across the entire lens for distance vision.

Pro tip: If you’re ever unsure about the details of your prescription, don’t hesitate to ask your optometrist for clarification.

Not at all. Prescriptions indicate how your eyes focus light and the correction needed for clear vision. A high or mild prescription can be addressed with the right lenses. There’s no such thing as a “bad” prescription.

Now that you know how to read your eyeglass prescription. Here's how to add your prescription to new frames on Mia Burton:

If you enter it manually, you’ll see some details we mentioned earlier. You’ll need to fill in the numbers for your right and left eye (SPH, CYL, AXIS), plus your optional Pupillary Distance (PD). Easy as that. Your custom glasses will be on their way in no time.

For most people, it’s natural for prescriptions to evolve, especially as they age or strain their eyes frequently. Changes can happen gradually, often due to aging or increased screen time. Regular eye exams are the best way to stay on top of these changes and ensure clear vision. Depending on the laws in your country, eye prescriptions typically expire after one or two years. To renew, simply schedule a new eye exam.

Now that you know how to read a prescription for eyeglasses, it’s time to find the perfect pair. Whether updating your current look or picking out something new, understanding your prescription is the first step toward seeing the world.

Ready to shop for your perfect pair? Check out our selection of stylish, high-quality frames tailored to your prescription with free anti-reflective lenses starting at $94.

Are you looking for designer frames instead? Explore our curated picks of designer frames to pair with your prescription lenses.

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