How to Read Your Eyeglass Prescription

Match your paper prescription values to the checkout fields using this guide, or upload a photo of your sheet so our team can handle it for you.

OD vs. OS: Which Eye Is Which?

• OD (Oculus Dexter): Right eye.

• OS (Oculus Sinister): Left eye.

• OU (Oculus Uterque): Both eyes.

What Your Prescription Numbers Mean

• SPH (Sphere): Your main prescription strength. A minus sign (-) means nearsightedness; a plus sign (+) means farsightedness.

• CYL (Cylinder): Corrects astigmatism. If you have a CYL number, you must also have an AXIS number.

• AXIS (1 to 180): The angle orientation for your astigmatism correction.

• ADD: Magnifying power added for reading or multifocal lenses (Progressives/Bifocals).

• PRISM: Special correction used for eye alignment.

Important Rules Before You Order

• Glasses vs. Contacts: Do not use a contact lens prescription for eyeglasses! They sit at different distances from the eye and use completely different measurements.

• Missing PD (Pupillary Distance)? Eye doctors often leave PD off paper prescriptions. You can measure your PD in seconds using our online tool during checkout.

• High Prescription Values (+/-4.00 SPH or higher): Select thinner high-index lenses during checkout to prevent heavy, thick lenses.

Fast Chat Commands

Open Live Chat and type:

• Upload a photo of your prescription: Type "Upload prescription"

• Help entering your numbers: Type "Help placing an order"