Guide to Understanding Your Eyeglasses Prescription

You finish your exam. You feel great. Then the doctor hands you a slip of paper.

You look at it, and it looks like a math equation gone wrong. There are plus signs, minus signs, and abbreviations that look like Latin (because they are). It feels like a secret code that only an optometrist near you can decipher.

But it’s not a secret. It’s actually a very precise recipe for how you see the world.

At Visionary Eye Care, we believe you should know exactly what is going on with your eyes. Here is a quick guide to decoding that piece of paper.

The Left and The Right

First, you will see the letters OD and OS.

• OD (Oculus Dexter): This is the Latin term for your "Right Eye."
• OS (Oculus Sinister): This is the Latin term for your "Left Eye."

If you see OU, that means "Both Eyes."

The Sphere (SPH)

This is the main part of your prescription. It measures the lens power needed to correct your vision.

• The Minus Sign (-): If your number has a minus (like -2.50), you are nearsighted. You have trouble seeing things far away, like road signs.
• The Plus Sign (+): If your number has a plus (like +1.75), you are farsighted. You struggle more with things up close.

The higher the number, the stronger your eyeglasses need to be.

Cylinder (CYL) and Axis

These two numbers go together. They handle astigmatism.

If you have numbers here, it means your cornea isn't perfectly round like a basketball; it’s shaped more like a football. This causes distortion at all distances. The cylinder indicates how much astigmatism you have, and the axis tells the lab exactly where to position the correction in your lenses.

The "Add"

If you are over 40, you might see a number under "ADD." This stands for Addition. It is the extra magnifying power added to the bottom of your lenses for reading or bifocals.

Call Our Eye Doctors Near You to Schedule a Visit Because Accuracy Matters

That slip of paper is a blueprint. To get the best vision, you need a team that follows that blueprint perfectly. If you are looking for eyeglasses near you in Elizabeth City, NC, come see us. We turn those numbers into crystal-clear vision. Call Visionary Eye Care at (252) 512-5004 today to update your prescription.