This guide explains everything on your eyeglass prescription so you can order rimless glasses online with confidence. Your prescription is a medical document — if anything is unclear, contact your optician to confirm before ordering.
Reading Your Prescription
OD / OS: OD = right eye (oculus dexter), OS = left eye (oculus sinister). Some prescriptions also show OU (both eyes). SPH (Sphere): The main power of the lens. Negative numbers (-) = myopia (short-sightedness). Positive numbers (+) = hyperopia (long-sightedness). CYL (Cylinder): Astigmatism correction. May be blank or 0 if you have no astigmatism. Axis: The orientation of the astigmatism correction in degrees (1–180). Only present if CYL is non-zero. ADD: The additional reading power for progressive or bifocal lenses. Typically +1.00 to +3.50. PD (Pupillary Distance): The distance between your pupils in millimetres. Essential for prescription glasses. May be listed as a single number (binocular PD, e.g., 63mm) or two numbers (monocular PD, e.g., R:32 L:31).
Which Lens Index Do I Need?
For rimless glasses, the lens index determines how thick the edges will be. Standard 1.50: Prescriptions up to ±2.00. 1.60 high-index: ±2.00–4.00 (20% thinner). 1.67 high-index: ±4.00–6.00 (35% thinner). 1.74 ultra-high-index: Over ±6.00 (45% thinner). For rimless glasses, we always recommend going one index higher than you might in a full frame — the exposed lens edge makes thinness more important.
Measuring Your PD at Home
Stand 20cm from a mirror. Hold a ruler against your brow. Close your right eye and align the ruler’s 0mm with the centre of your left pupil. Open your right eye, close your left, and read the measurement at your right pupil centre. This is your binocular PD. Average adult PD is 60–68mm. If your two eyes differ by more than 1mm, please enter both monocular measurements separately.
Questions?
Our opticians review every order before it goes to the lab. If there’s anything unusual in your prescription, we’ll contact you before proceeding. You can also contact us with any prescription questions before ordering.