If you've ever picked up a glasses prescription from your optician and stared at it in complete bafflement, you are absolutely not alone. A row of numbers, plus and minus signs, and abbreviations that look more like a maths exam than anything to do with eyesight can feel quite daunting. The good news is that once someone explains what each bit means, it all makes a great deal more sense.
When you visit us at LG Optical in St Leonards-on-Sea, you are welcome to bring your prescription along and we will help you make sense of it as part of finding the right frames and lenses for you. But here is a plain-English guide to get you started.
SPH, CYL and AXIS: The Core Numbers Explained
SPH (Sphere) is the main correction your lenses need to give you. A minus number means you are short-sighted (you struggle to see things in the distance), while a plus number means you are long-sighted (close work such as reading can be difficult). The higher the number, the stronger the correction needed.
CYL (Cylinder) relates to astigmatism, which simply means the front surface of your eye is slightly irregular in shape rather than perfectly round. Not everyone has a CYL value; if this box is blank or reads "0.00", you have no astigmatism to correct for. Like SPH, it can be a plus or minus number.
AXIS only appears when there is a CYL value, and it is always a number between 1 and 180. It tells the lens maker the exact angle at which the astigmatism correction needs to be positioned. On its own it means nothing; it only works in combination with the CYL figure.
ADD, PD and Why They Matter for Your Lenses
ADD (Addition) is the extra magnification needed for reading or close work, and it only appears on prescriptions for people who need varifocal or bifocal lenses, or separate reading glasses. This is very common from your mid-forties onwards as the eyes naturally lose some flexibility. The ADD value is usually the same for both eyes and is always a plus number.
PD (Pupillary Distance) is the measurement in millimetres between the centres of your pupils. It is essential for making sure your lenses are positioned correctly within the frame so you are looking through the right part of each lens. Some opticians include it automatically; others do not, so it is worth asking for it when you collect your prescription.
You will also see RE/OD and LE/OS on your prescription. These simply mean right eye and left eye respectively, using the traditional Latin abbreviations.
Armed with this knowledge, that piece of paper suddenly looks a lot less mysterious. When you come in to browse our large showroom here in Hastings, our team can talk you through exactly what your prescription means for your lens choices, whether that is single vision, varifocal, bifocal or Transitions lenses.
There is no rush and no pressure. Come in, have a browse, try on plenty of frames, and let us help you find a look you will love.
LG Optical is based at St Leonards-on-Sea, Hastings. Appointments not always necessary, just call ahead on 01424 851878 and bring your current prescription with you.
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