Key Takeaways
- Letters like O.D. and O.S. identify your right and left eyes.
- Measurements indicate your overall lens power and astigmatism details.
- Plus and minus signs show if you need help with near or far vision.
- Contact lens measurements include specific shape details for a proper fit.
- Regular visits to an eye doctor in Chula Vista help maintain clear sight.
Reading Your Eyeglass Prescription
After your vision exam at Total Vision Terra Nova, you’ll receive a small slip of paper with your prescription on it, the details of which might look like a secret code. Fortunately, it’s easy to explain all the medical shorthand, so that you can pick out new frames and lenses without any extra stress.
You can read your glasses prescription by identifying the abbreviations for your right and left eyes along with the numbers that show your vision needs. A basic understanding of these terms helps you make informed choices about your next pair of glasses.
Right & Left Eye Abbreviations Explained
Oculus Dexter for Your Right Eye
You can find the letters O.D. near the top of your vision paperwork. This Latin term simply means your right eye. The numbers in this row show how much correction your right eye needs for clear sight.
Oculus Sinister for Your Left Eye
The letters O.S. stand for your left eye. You may see different numbers here because each of a person’s eyes often requires a different level of correction. Your left eye might have crisp vision, while your right eye needs a little help reading a menu. You might also spot the letters O.U. printed on the page to show a measurement for both eyes tested together.
Sphere, Cylinder & Axis
Sphere Shows Your Overall Power
The Sphere or SPH section points to the overall strength that your lenses need to function properly. The SPH value is measured in units called diopters. A larger number in this column means you need a stronger lens to correct your vision.
Cylinder & Axis Describe Astigmatism
The Cylinder or CYL column on your paperwork. This measurement helps correct an irregularly shaped cornea associated with a diagnosis of astigmatism.
The Axis has a similar function—it describes the exact angle of your astigmatism. Empty boxes in these columns mean that you don’t need correction for astigmatism.
Add Value for Multifocal Lenses
The ADD section provides extra magnifying power for your lenses. This extra boost helps you handle near vision tasks like reading a book or checking your phone. You see this measurement frequently for reading glasses and bifocals to treat age-related vision changes.
How Plus & Minus Numbers Affect Your Vision
Minus Signs for Nearsightedness
A minus sign on your prescription means you’re nearsighted and need help seeing distant objects clearly. Higher minus numbers mean that you need thicker and more powerful lenses to correct your vision.
Plus Signs for Farsightedness
A plus sign indicates that you need assistance seeing close-up objects clearly. The higher the number, the stronger the correction you require.
Differences Between Glasses & Contact Prescriptions
Specific Contact Lens Measurements
Because contact lenses sit directly on your eyes, they require a few additional measurements. These include Base Curve, which describes how the contacts should fit the shape of your eyes, as well as Diameter, which indicates the width of the lenses you need.
Why These Two Prescriptions Differ
Glasses sit a bit away from your face, on the bridge of your nose, whereas contact lenses rest directly on your eyes. This difference in position affects the strength of the lenses needed to correct a person’s vision. As a consequence, prescriptions for glasses and contact lenses actually aren’t interchangeable.
If you’re interested in contacts, you’ll need to schedule a contact lens fitting.
When to Visit an Eye Doctor in Chula Vista
Signs Your Prescription Needs an Update
Your vision can change subtly over time. Paying attention to these physical cues can help you realize when it’s time to pay your optometrist a visit:
- Squinting to see road signs clearly
- Frequent headaches after reading a book
- Blurry vision while looking at a screen
Routine Exams for Your Family
As your eye doctor in Chula Vista, our team at Total Vision Terra Nova provides preventative eye care for everyone in your household. Schedule your next eye exam today to help keep your eyesight clear.
