When ordering progressive lenses online, one measurement stands above all others — Pupillary Distance (PD). Get it wrong, and even a perfectly crafted progressive lens will leave you with blurry vision, headaches, and eye strain. This guide explains what PD is, why it is non-negotiable for multifocal lenses, and how to measure it accurately before placing your order.
Your optometrist hands you a prescription with numbers and abbreviations that look like a foreign language. SPH, CYL, Axis, ADD, PD — what does it all mean? This simple, jargon-free guide explains every term on your prescription so you can confidently order your glasses online at NationsOptics.