Plano means zero, so no lens power is needed there. It shows up on a prescription as PL, PLANO or 0.00, almost always in the sphere column. It is not an error or a blank waiting to be filled in. It means that particular correction is not required for that eye.
Where plano appears on the form
It sits in the SPH column, short for sphere, which covers nearsightedness and farsightedness. A minus number there means nearsighted, a plus number means farsighted, and plano means neither one applies. The word shares a root with plane, meaning flat, a reference to a lens surface with no curvature grinding power into it.
Offices write it differently. Some use PL, some spell out PLANO, some write 0.00, and some draw an infinity symbol. They all mean the same thing, and a lab reads them the same way.
Three reasons plano turns up
- You have astigmatism but no sphere correction. The sphere column reads plano while CYL and AXIS carry real numbers. The lens still gets made. It corrects the shape of the focus rather than the distance.
- Only one eye needs correction. The other eye is written plano so the lab knows to cut a matching lens with no power, keeping both sides similar in thickness and appearance.
- The eyewear is not corrective at all. Plano safety glasses, plano sunglasses and plano colored contact lenses are all zero power by design.
What the rest of the abbreviations mean
| Abbreviation | What it means |
|---|---|
| OD | Oculus dexter, the right eye |
| OS | Oculus sinister, the left eye |
| OU | Both eyes together |
| SPH | Sphere, the main correction. Minus for nearsighted, plus for farsighted, plano for none |
| CYL | Cylinder, the amount of astigmatism correction |
| AXIS | The orientation of that cylinder, written from 1 to 180 degrees |
| ADD | Added magnifying power for reading, used in bifocals and progressives |
| PD | Pupillary distance, the gap between pupils, used to center the lenses |
| PRISM and BASE | Correction for eye alignment and the direction it is set |
| DV and NV | The distance vision and near vision portions of the prescription |
| BAL | Balance lens, matched for appearance when an eye gets no usable correction |
Does plano mean 20/20 vision?
No, and the two describe different things. A prescription records what correction your eyes need in order to focus light. The 20/20 figure records how much detail you can resolve on a chart. A plano sphere paired with a cylinder number still means blurry vision without lenses.
Plenty of eye conditions have nothing to do with refraction either, which is why a full exam looks at more than the numbers in those columns. Anything about the health of your eyes belongs with your optometrist or ophthalmologist rather than a lens retailer.
Before you order glasses online
- Check that you have the pupillary distance. Prescriptions do not always include it, and an online order needs it.
- Make sure you are using a glasses prescription and not a contact lens one. Contacts sit directly on the eye and add base curve and diameter, so the two are never interchangeable.
- Confirm the expiration. How long a prescription stays valid depends on state rules and on the practice, so ask your provider instead of assuming a standard period.
- If a column is blank rather than marked plano, call the office and ask them to confirm it. A blank is ambiguous. Plano is not.
One more habit worth keeping. Save a photo of every prescription you are given. Comparing this year against last year is the easiest way to notice a column that moved more than you expected, which is a reasonable thing to ask about at the next exam.
