What does my glasses prescription mean?

Ever wonder what all those numbers on your glasses prescription mean? Here’s a quick explanation!  Your Rx may range from 1-4 or more numbers looking something like this:

        Sphere•   Cylinder   •   Axis   •   Add

OD+3.00            -0.25         090       +2.00

OS    -7.00          -2.75          168         +0.75

↑          ↑                 ↑                ↑              ↑

1          2                3                4              5

If you see great far away your eye power may be 0 or close to 0.

If your eyes have too much power, you need MINUS lenses to see clearly far away.

If your eyes don’t have enough power they may be able to compensate and focus using your eye muscles. But this may cause eyestrain and may require glasses with PLUS lenses.

  1. The first column tells you which eye the row refers to, since your eyes can require different prescriptions.  OD (Ocular Dexter) refers to the right eye, and OS (Ocular Sinister) refers to the left eye.  (“Dexter” and “Sinister” are Latin for right and left.)
  2. The first number tells you if you’re nearsighted (eyes have too much power – needing a MINUS Rx) or farsighted (eyes have too little power – needing a PLUS Rx). The number there may also be 0 or “plano”.
  3. The second number is for when you have astigmatism which means that your eye having an oblong shape. Imagine the eye being more football shaped than basketball shaped. A small amount may not affect vision much, but more can cause blurred vision.
  4. The third number tells us the orientation of the “football”.
  5. The fourth number is for when you need a reading prescription as well. That number is always a plus number.

Keep in mind some prescriptions may include more than what is explained here so if you have any further questions regarding your prescription your doctor will be happy to explain!

Contact us for more assistance at 510-654-4747 for more assistance at 510-654-4747