HOW TO READ YOUR EYEGLASS PRESCRIPTION

YOUR EYEGLASS PRESCRIPTION DECODED

Your eyeglass prescription is typically written in a grid like the one below, using a combination of terms, abbreviations, and numbers.

Usually you’ll see these abbreviations along the left side:

• O.D. stands for oculus dexter, meaning right eye.
• O.S. stands for oculus sinister, meaning left eye.

Then along the top, you may see this lingo.
These abbreviations reflect the measurements of specific aspects of your vision, and can be pretty confusing at first.

• SPH (or Sphere) indicates the eyeglass prescription power, or how strong your lenses need to be to correct your vision.
• CYL (or Cylinder) indicates astigmatism, a condition where the cornea is irregularly shaped causing blurred or distorted vision. It also tells the lens strength needed to fix it.
• AXIS describes the degree and direction of your astigmatism.
• ADD is added magnifying power in the lower part of a multi-focal lens. It’s used to correct presbyopia which is the inability to focus on close objects. If you need a bifocal or progressive lens, there will be an ADD.