- posted: Dec. 10, 2025
Understanding your eyeglass prescription can feel a little confusing when you first look at it, especially with all the abbreviations, numbers, and eye-specific measurements. At Stone Oak Ophthalmology Center in San Antonio, TX, we help patients interpret their prescriptions so they know exactly what kind of vision correction they’re receiving. If you’re searching for an ophthalmologist near you to update your lenses or get glasses for the first time, understanding your prescription gives you the confidence to make informed decisions about your eye care.
What OD and OS Mean on Your Prescription
One of the first things patients notice is the use of OD and OS. OD refers to your right eye, while OS refers to your left eye. These terms come from Latin and simply help the ophthalmologist label each eye’s correction needs. When you understand which numbers belong to which eye, the rest of the prescription becomes much easier to interpret.
Sphere (SPH): Correcting Nearsightedness or Farsightedness
Sphere, often written as SPH, indicates the overall strength of the lens you need. A minus sign means you are nearsighted, while a plus sign means you are farsighted. Patients often notice this number appears alongside other measurements, providing the foundation for their corrective lenses.
Cylinder (CYL) and Axis: For Astigmatism Correction
Astigmatism occurs when the cornea has an uneven curve, causing blurry or distorted vision. If your prescription includes CYL and Axis values, these numbers identify both the degree and the orientation of the astigmatism. Many patients searching for astigmatism treatment near you rely on these two numbers to understand how their lenses will compensate for the irregular shape of the eye.
ADD and Other Supplemental Values
Some patients, especially those who need help with reading or close-up work, will see an ADD value on their prescription. This number indicates the additional magnification required for tasks like reading or sewing. Your ophthalmologist may also include pupillary distance (PD), prism corrections, or other notes that ensure your glasses are customized to your visual needs.
Your Prescription Is the First Step to Clearer Vision
A clear understanding of your eyeglass prescription helps you feel confident when choosing frames, ordering lenses, or exploring advanced care options such as astigmatism treatment. Stone Oak Ophthalmology Center is here to guide you through every part of the process. If you’re looking for an ophthalmologist near you or need help interpreting your prescription, call us at  (210) 490-6759 . Let us help you take the next step toward sharper, more comfortable vision.
- posted: Dec. 10, 2025
Understanding your eyeglass prescription can feel a little confusing when you first look at it, especially with all the abbreviations, numbers, and eye-specific measurements. At Stone Oak Ophthalmology Center in San Antonio, TX, we help patients interpret their prescriptions so they know exactly what kind of vision correction they’re receiving. If you’re searching for an ophthalmologist near you to update your lenses or get glasses for the first time, understanding your prescription gives you the confidence to make informed decisions about your eye care.
What OD and OS Mean on Your Prescription
One of the first things patients notice is the use of OD and OS. OD refers to your right eye, while OS refers to your left eye. These terms come from Latin and simply help the ophthalmologist label each eye’s correction needs. When you understand which numbers belong to which eye, the rest of the prescription becomes much easier to interpret.
Sphere (SPH): Correcting Nearsightedness or Farsightedness
Sphere, often written as SPH, indicates the overall strength of the lens you need. A minus sign means you are nearsighted, while a plus sign means you are farsighted. Patients often notice this number appears alongside other measurements, providing the foundation for their corrective lenses.
Cylinder (CYL) and Axis: For Astigmatism Correction
Astigmatism occurs when the cornea has an uneven curve, causing blurry or distorted vision. If your prescription includes CYL and Axis values, these numbers identify both the degree and the orientation of the astigmatism. Many patients searching for astigmatism treatment near you rely on these two numbers to understand how their lenses will compensate for the irregular shape of the eye.
ADD and Other Supplemental Values
Some patients, especially those who need help with reading or close-up work, will see an ADD value on their prescription. This number indicates the additional magnification required for tasks like reading or sewing. Your ophthalmologist may also include pupillary distance (PD), prism corrections, or other notes that ensure your glasses are customized to your visual needs.
Your Prescription Is the First Step to Clearer Vision
A clear understanding of your eyeglass prescription helps you feel confident when choosing frames, ordering lenses, or exploring advanced care options such as astigmatism treatment. Stone Oak Ophthalmology Center is here to guide you through every part of the process. If you’re looking for an ophthalmologist near you or need help interpreting your prescription, call us at  (210) 490-6759 . Let us help you take the next step toward sharper, more comfortable vision.