How to Read Your Eye Prescription — SPH, CYL, AXIS, ADD Explained
Introduction
Did your eye doctor hand you a prescription, but you’re staring at it like it’s in a different language? Abbreviations like SPH, CYL, AXIS, ADD, and PD can be confusing. Don’t worry—understanding your prescription is easier than you think. Let’s break it down in simple terms.
OD and OS: What do they mean?
- OD (Oculus Dexter): Right Eye
- OS (Oculus Sinister): Left Eye
- OU (Oculus Uterque): Both Eyes
Understanding the Key Abbreviations
1. SPH (Sphere) — The Primary Power
This is the core of your vision correction.
- Negative (-) Sign: Myopia (Nearsightedness). You struggle to see distant objects.
- Positive (+) Sign: Hyperopia (Farsightedness). You struggle to see near objects.
- 0 or Plano: No distance power needed.
2. CYL (Cylinder) — Astigmatism Power
This measures your astigmatism—the degree to which your cornea is shaped like a football rather than a basketball. If this column is empty, you don’t have astigmatism.
3. AXIS — The Direction
If you have a CYL value, you must have an AXIS value (0 to 180 degrees). It tells the lens maker where to place the astigmatism correction.
4. ADD — Reading Power
Commonly found in Bifocal or Progressive lenses. It adds extra power to the bottom portion of your lens for reading small print. It is always a positive (+) number.
5. PD (Pupillary Distance)
The distance in millimeters between the centers of your pupils. Accurate PD ensures your lenses are centered correctly in the frame.
Why Is It Dangerous to Use Old Prescriptions?
Your eye power can change due to lifestyle, stress, or age. Using a prescription older than 2 years can cause chronic eye strain, headaches, and in some cases, further vision deterioration.
Frequently Asked Questions (FAQ)
Q: At what power do I need glasses?
A: Generally, ±0.50 or higher power warrants the use of glasses for clearer vision.
Q: Can I order glasses online without a prescription?
A: For Zero Power glasses, you don’t need one. However, for any vision correction, a recent prescription is mandatory for your health.
Q: What if my prescription doesn’t have a PD value?
A: Don’t worry! You can type “PD not known” in the Order Note on OpticoBD, and our team will guide you on how to measure it.
Conclusion
Now you know how to read your prescription like a pro! However, for your eye health, accuracy is non-negotiable. The best way to get perfect vision is to upload your prescription directly to OpticoBD, and let our experts verify everything before crafting your lenses.
👉 Upload Your Prescription at OpticoBD.com and Order with Confidence!
