How to Read the Prescription of Your Contact Lenses?


Do you remember the day when your optician told you that your eyesight is not 6/6 anymore? And how bad you felt on the thought of wearing glasses? But then, we all, at some point in our lives, were introduced to contact lenses. They act as a golden ticket to the glasses-free face with a perfect vision.

Well, if you are one of the people who wear contact lenses, then you must also know how to read your prescription. If you do not know it yet, give this article a good read and within 10 minutes, you will!

What do the Abbreviations mean?

All we understand in a prescription are the numbers written. What we do not know is what do the abbreviations that these numbers indicate stand for.

Let us have a look at these abbreviations:-

  • DV and NV- Abbreviations of Distance Vision and Near Vision respectively, these determine whether a correction is required or not. In case both of them contain numbers, multifocal lenses are required.
  • Brand- The brand of contact lenses your doctor fitted for your eyes.
  • DIA- DIA or diameter is the distance across the surface of the lens. Measured in millimeters, it is between 13 and 15 and decides where the lens sits on an individual’s eye.
  • BC- Measured in millimeters, the Base Curve is the back curvature of the contact lens. Generally, this number is between 8 and 10. The curvature is supposed to match the curve of the cornea so that the lenses fit in the eye properly.
  • SPH- Sphere, also called as PWR or Power, is the strength of lens required. Myopic lenses (nearsighted) range from -20.00 to -0.05, while Hyperopic lenses (farsighted) range from +0.05 to +20.00.
  • OD- It stands for Oculus Dexter. This Latin word is used to represent the right eye.
  • OS- Oculus Sinister is a Latin word for the left eye.

What are Astigmatism-Correcting Lenses?

Astigmatism refers to a defect that may result in distorted images. To correct this, the prescriptions contain two numbers separated by an ‘X’. They are indicated using these abbreviations:

  • AX: Axis indicates where the lens correction or cylinder has to be placed. Generally, it is between 0 and 180 degrees.
  • CYL: Cylinder (Generally, it is between -4.00 and +4.00.)

Multifocal or Bifocal

The lenses that are bifocal or multifocal contain prescriptions that have an additional number with the given abbreviation:

  • ADD: This is also referred to as Extra Strength or Add Power.
  • Dominant: In the case of a multifocal or bifocal lens, the lens correction is determined by a dominant and non-dominant eye. Hence, D and N are marked for each eye representing which one is dominant and which is not respectively.

Can You Buy Contact Lenses Without Prescription

In many places, you may not be sold contact lenses without a prescription. However, there are certain websites that sell them without the requirement of a prescription. One of these is If you wish to buy contact lenses without a prescription, then this website is just right for you. You will not only get a range of choices but will also get them at affordable prices.

Although one can buy them without being prescribed, it is better to get a prescription before buying lenses. And once you have a prescription, you must know how to read it.