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How to Read Your Eyeglass Prescription Online in Pakistan (SPH, CYL, AXIS & PD Explained)
Getting your eyes tested by an optometrist or ophthalmologist is the first step toward clear vision. But when you look at your prescription slip, you often see terms like SPH, CYL, AXIS, ADD, and PD with plus and minus numbers that can feel confusing.
Understanding these numbers is simple, and knowing what they mean empowers you to order your prescription glasses online with complete confidence. Here is a breakdown from the optical experts at Haidery Optical (Haiop.com).
Key Abbreviations on an Eyeglass Slip
1. OD and OS (Which Eye?)
- OD (Oculus Dexter): Latin for your Right Eye.
- OS (Oculus Sinister): Latin for your Left Eye.
- OU (Oculus Uterque): Refers to Both Eyes.
2. SPH (Sphere – Vision Power)
The Sphere indicates the amount of lens power needed to correct nearsightedness or farsightedness, measured in diopters (D):
- Minus (-) Sign (e.g. -2.00): Means you have Myopia (Nearsightedness). You can see objects close to you clearly, but distant objects appear blurry.
- Plus (+) Sign (e.g. +1.75): Means you have Hyperopia (Farsightedness). You see distant objects well, but close objects or reading text are blurry.
3. CYL (Cylinder) & AXIS (Astigmatism Correction)
- CYL (Cylinder): Indicates the lens power needed to correct Astigmatism (an irregularly shaped cornea that causes blurred or stretched vision at all distances). If this box is blank or says “SPH”, you do not have astigmatism.
- AXIS (1 to 180 degrees): If you have a CYL number, you will always have an AXIS number. It describes the exact orientation or angle where the astigmatism correction needs to be placed on the lens.
4. ADD (Near Vision Addition for Reading)
The ADD power is used for multifocal, bifocal, or progressive lenses. As people reach age 40+, natural focusing power decreases (presbyopia). The ADD number (usually between +0.75 and +3.00) indicates the magnifying power added to the bottom of the lens for comfortable reading.
5. PD (Pupillary Distance)
Pupillary Distance is the distance between the centers of your pupils in millimeters (typically between 58mm and 68mm). Having the correct PD ensures the optical center of the lens aligns directly in front of your pupils for crystal-clear, distortion-free vision without headache or eye strain.
Common Eyeglass Prescription Example
| Eye | SPH | CYL | AXIS | ADD |
|---|---|---|---|---|
| OD (Right) | -2.50 | -0.75 | 90 | +1.50 |
| OS (Left) | -2.00 | -0.50 | 85 | +1.50 |
How to Order Prescription Glasses Online at Haidery Optical
Ordering prescription eyeglasses online in Pakistan has never been easier:
- Select your favorite frame from our Eyeglasses Collection.
- Take a clear photo of your prescription slip from your eye doctor.
- Send the photo on WhatsApp to 0333 3258832 or upload it during checkout.
- Our licensed lab optometrists will cut and fit genuine multi-coated or blue-cut lenses into your chosen frame with precision computerized edging.
- Receive your complete glasses at your doorstep anywhere in Pakistan with Cash on Delivery!