At DigiVision Optical, we believe that clear vision starts with understanding your eye exam results. After your comprehensive eye exam in Lansing or East Lansing, you’ll receive an eyeglass prescription that’s filled with numbers and abbreviations. This guide will help you read and understand what those measurements mean — so you know exactly how your prescription affects your vision.
What’s on Your Prescription?
Your eyeglass prescription is more than just a piece of paper — it’s a personalized map for sharper, more comfortable vision. Here’s what the most common terms and abbreviations mean:
OD and OS
- OD (Oculus Dexter) – Right Eye
- OS (Oculus Sinister) – Left Eye
- Sometimes you’ll also see OU (Oculus Uterque), which means both eyes.
Sphere (SPH)
- Measures the overall lens power needed to correct nearsightedness or farsightedness.
- A minus (-) sign means you are nearsighted (distant objects are blurry).
- A plus (+) sign means you are farsighted (close objects are blurry).
Cylinder (CYL)
- Shows the amount of astigmatism correction you need. Astigmatism occurs when your cornea or lens is shaped more like a football than a basketball, causing blurred or distorted vision.
Axis
- A number between 1 and 180 that tells the lab where to place the astigmatism correction in your lenses.
- Think of it as the direction of your astigmatism.
Add
- Stands for “Addition” and is used for multifocal or progressive lenses.
- It indicates the extra magnifying power for reading or near work.
Prism
- Corrects for eye alignment problems that may cause double vision.
- Measured in prism diopters and paired with a base direction (up, down, in, or out).
Why Understanding Your Prescription Matters
Knowing how to read your prescription helps you:
- Choose the right eyeglass lenses (single vision, bifocal, progressive).
- Understand why your vision feels a certain way without correction.
- Make informed decisions when selecting lens upgrades such as anti-reflective coating, blue light protection, or transition lenses.
Common Prescription Examples
| OD (Right Eye) | Sphere | Cylinder | Axis | Add |
|---|---|---|---|---|
| -2.00 | -0.50 | 90 | +2.00 | – |
This means:
- Right eye is nearsighted (-2.00 SPH).
- Has mild astigmatism (-0.50 CYL) at 90°.
- Needs a +2.00 boost for near vision.
Local, Personalized Eye Care
At DigiVision Optical in Lansing and East Lansing, we take the time to explain your prescription in plain English. Whether you need eyeglasses, contact lenses, or a specialized vision solution, our experienced optometrists and optical team ensure your lenses are crafted precisely to your needs.