How to Read My Prescription?
The basic function of optical glasses is vision correction. To place an order for prescription glasses, you need to have a prescription for corrective eyeglass lenses and your pupillary distance.
NOTE: If you obtain a contact lenses prescription, you can’t use it to make eyeglasses order.
If you can't make out what's written on your prescription, there will be No Worries. Just post it to us with your order by our friendly Online Support or email it to service@eGlassesStore.com, and we’ll do our best understand it. If we can’t, we’re likely to ask you to go back to your optician and get them to explain it. It’s worth knowing that all opticians are legally bound to give you a clear, legible copy of your prescription to take home.
On a typical prescription, you will see two sets of rows. Mostly top portion is for your OD or right eye while the bottom portion is for your OS or left eye.
Prescriptions are generally laid out as follows:
- Please pay close attention to plus and minus signs as it will affect your lens.
SPH
Sph - Provides the depth of the focal field in the lens.
For Distance correction, there should always be a value under Sphere and most of the time it is negative. Its abbreviation is 'D.V.' or Distance Vision.
For Reading-only correction, there should always be a value under sphere and most of the time it is positive.
CYL and AXIS
Please note that Cylinder (CYL) and Axis are always provided together. For any value of Cylinder there should always be a value for Axis. The two designations may be included if you have an astigmatism, an irregularity in the shape of the eye, which causes shape distortion in the viewed image.
Cyl should be a number between +/-4, in 0.25 increments.
Doctors will often use positive (+) cylinder but some use negative (-), there is a BIG difference between the two so please pay close attention to the signs.
Axis should be from 1-180 degrees. If you see a number like ‘6’ under axis, it is also the same as ‘006’ or ‘6 degrees.’ It should always be a whole number and never with a decimal point on the axis.
ADD or Near Addition
The Add is mostly for people over 40 and concerns bifocal/progressive reading and near correction. This is the reading portion of a lens in a multi-focal prescription, and this number indicates the strength of the overlay on the lens, for reading.
Sometimes opticians write the addition as a complete additional line on your prescription, sometimes once (same for both eyes) and sometimes once for each eye. Only one ADD means that the addition for both the left and right eyes are the same.
If you have a prescription for multi-focal glasses but only want to purchase single-vision lenses for distance correction, just leave off the ADD part which is for the bottom near or reading correction of the bifocal. If you are ordering reading glasses, please keep the ADD on the prescription.
PD
This measurement is necessary to ensure the correct positioning of your lenses within the frame you have chosen.
The PD or Pupillary Distance is the distance between your two eyes , center to center, the center of one pupil to the center of the other, in Millimeters.
