There are many people look at their prescriptions and see only a confusing jumble of numbers, symbols, and abbreviations.
It is easy to understand, you can try to order first, then you will find that the prescription you need input on our site, which is the same form as yours. So just compare with them and enter it.
The following guide will help you decipher this important information.
Here are some examples of how your prescription might look:
Let’s translate the abbreviations.
- O.D. = right eye. In sample 1, the top row contains measurements for the right eye.
- O.S. = left eye. In sample 1, the bottom row contains measurements for the left eye.
- SPH = SPHERE power, or the main correction power which corrects refractive error.
- CYL = CYLINDER power corrects astigmatism refractive error.
- AXIS = shows where an astigmatism is located along the eye’s horizontal axis.
- ADD = the amount added to the sphere (SPH) value for those requiring reading glasses, bifocal or progressive lenses.
- P.D. = pupillary distance, the distance from the center of the pupil from one eye to the other.
- PRISM = indicates the image’s displacement value through the lens for those with unusual conditions like a squint or lazy eye.
Some other abbreviations you might see:
- D.S. or DS = diopters sphere which indicates that you have only a sphere value and no cylinder value; therefore you need no correction for astigmatism.
- D.V. = distance vision
- N.V. = near vision, sometimes written as N.V.O.
- O.U. = both eyes
- X = axis
Extra tips
- For distance correction, most of the time the value under sphere is negative.
- For reading-only correction, most of the time the value under sphere is positive.
- Please ensure that you get the + or – symbol correct. This will make a huge difference to the accuracy of your lenses.
- If some of the boxes on your prescription are blank (e.g. no CYL or AXIS or ADD values), leave those boxes blank when ordering.
- If you have a value under “Near Vision” (N.V., N.V.O.) then enter the power in the BOTTOM half of the form and leave the ADD power blank or ("0.00").
- For bifocal and progressive lenses, please check with your optometrist whether the Addition (ADD) value is for bifocals or progressives.
- Sometimes optometrists will leave out the decimal point on the Sphere, Cylinder and Addition values. For example, -25 is understood as -0.25, and +175 is +1.75.
- If you see a PAL note written on the prescription, then this simply indicates that your prescription is for PROGRESSIVE lenses.
- Please be advised that we process a minimum of +1.00 and maximum of +3.00 for ADD powers.
If there is anything else on the prescription that you are confused about, please call or e-mail our Customer Service and we’ll be happy to assist you.