Read Your Child’s Glasses Prescription With Confidence
A child’s glasses prescription contains the lens powers and measurements needed to make their prescription lenses. Common fields include OD, OS, SPH, CYL, AXIS, and PD.
You do not need to calculate or change these values. The important part is identifying each field and entering every number and sign exactly as written.
What Information Is on a Child’s Glasses Prescription?
Most prescriptions separate the right-eye and left-eye values. They may also include measurements for astigmatism, lens positioning, near vision, or prism correction.
Right Eye
OD identifies the prescription values for the right eye.
Left Eye
OS identifies the prescription values for the left eye.
Sphere Power
SPH shows the main prescription power for nearsightedness or farsightedness.
Cylinder Power
CYL shows the amount of astigmatism correction when prescribed.
Astigmatism Direction
AXIS shows the orientation of the cylinder correction.
Pupillary Distance
PD helps position the optical centers of the lenses correctly.
What Do SPH, CYL, AXIS, and PD Mean?
These are the most common fields parents need to recognize when ordering prescription glasses online.
Sphere
SPH shows the main lens power required for clearer vision.
- A minus sign usually indicates myopia or nearsightedness.
- A plus sign usually indicates farsightedness.
- A higher number represents stronger prescription power.
Cylinder
CYL shows the amount of lens power used to correct astigmatism.
- CYL may appear with a plus or minus sign.
- If it is blank, no cylinder correction may have been prescribed.
- Copy the sign and number exactly as written.
Axis
AXIS shows the orientation of the astigmatism correction.
- It is normally written as a number from 1 to 180.
- It is generally used only when a CYL value is present.
- AXIS is a direction, not a prescription strength.
Pupillary Distance
PD measures the distance between the centers of the pupils.
- Single PD uses one total measurement.
- Dual PD provides separate right-eye and left-eye measurements.
- Do not estimate a missing PD from the prescription power.
What Do ADD, NV, PRISM, and BASE Mean?
These fields do not appear on every child’s prescription. Enter them only when they are included in the original prescription.
ADD and NV
ADD means additional lens power for near vision. It may appear on prescriptions for bifocal, multifocal, progressive, or other lenses that include separate near correction.
NV usually refers to near vision. Its exact use may depend on the prescription format.
PRISM and BASE
PRISM may be prescribed for certain eye-alignment or binocular-vision needs. The prism number shows the amount of correction.
BASE identifies the direction of the prism and may be written as Base In, Base Out, Base Up, or Base Down.
How to Read the Prescription Step by Step
Work through the prescription in the same order each time to reduce entry mistakes.
Identify OD and OS
Find the right-eye and left-eye columns before entering any numbers.
Copy the SPH Values
Include the complete number and its plus or minus sign.
Check CYL and AXIS
When CYL is present, enter the corresponding AXIS for the same eye.
Look for Special Values
Check whether ADD, NV, PRISM, or BASE appears on the prescription.
Confirm the PD Format
Determine whether the prescription uses one total PD or separate right and left values.
Compare Before Submitting
Review every field against the original prescription before placing the order.
What Should Parents Check Before Ordering?
Complete one final review before submitting your child’s prescription glasses order.
The prescription is current and intended for eyeglasses.
OD and OS values are entered under the correct eyes.
All SPH, CYL, and AXIS signs and numbers match the prescription.
PD is entered using the correct single or dual format.
ADD, PRISM, BASE, and other special instructions are included when prescribed.
The selected frame measurements are suitable for the child.
What Does Our Team Check?
Potato Glasses reviews submitted prescription information for completeness and clarity before lens processing.
We may contact you when required information is missing, inconsistent, or difficult to read.
Use a Current Prescription
Eye-exam timing depends on your child’s age, prescription history, symptoms, and professional recommendation. Follow the examination schedule provided by your child’s eye care professional.