Eyeglass Prescription vs. Contact Lens Prescription: What’s the Difference?
Introduction
Many first-time buyers are surprised to learn that an eyeglass prescription and a contact lens prescription are not the same thing. Although both are designed to correct your vision, they contain different measurements because eyeglasses and contact lenses sit in completely different positions relative to your eyes.
This is one of the most common reasons customers experience confusion when ordering prescription glasses online. Someone may have a current contact lens prescription and assume it can be used to order glasses, only to discover that important information is missing.
In this guide, we’ll explain the differences between eyeglass and contact lens prescriptions, why they cannot usually be used interchangeably, what information each one contains, and how to make sure you’re using the correct prescription when ordering from Choice Eyewear.
By the end of this guide, you’ll know exactly which prescription you need and why using the correct one is so important for comfortable, accurate vision.
Quick Answer
No, you generally cannot use a contact lens prescription to order prescription eyeglasses.
Although both prescriptions correct your vision, they contain different measurements because:
- Eyeglasses sit approximately 10–14 mm in front of your eyes.
- Contact lenses rest directly on the surface of your eyes.
- Contact lenses require additional fitting measurements that eyeglasses do not.
If you’re ordering prescription glasses, you’ll need a current eyeglass prescription.
Why Are They Different?
Even though both prescriptions help you see clearly, the way they correct your vision is different.
Eyeglasses sit inside a frame in front of your face.
Contact lenses rest directly on the cornea (the clear front surface of your eye).
Because of this difference in position, the lens power and measurements required may not be the same.
Think of it like taking two photos with different camera lenses. The goal is the same—producing a clear image—but each lens requires different settings to achieve it.
What’s Included in an Eyeglass Prescription?
An eyeglass prescription tells the optical laboratory how to manufacture lenses for your glasses.
It may include:
- SPH (Sphere)
- CYL (Cylinder)
- AXIS
- ADD
- Prism (when prescribed)
- PD (Pupillary Distance), although this may sometimes be provided separately
These measurements determine how your lenses should be made and positioned within your eyeglass frame.
For a detailed explanation of each value, see our guide:
Understanding Your Eyeglass Prescription
What’s Included in a Contact Lens Prescription?
A contact lens prescription contains different information because contact lenses must fit safely and comfortably on the surface of your eyes.
In addition to vision correction, a contact lens prescription often includes:
- Brand or manufacturer
- Base Curve (BC)
- Diameter (DIA)
- Lens material
- Replacement schedule
- Expiration date
These measurements help ensure the contact lens fits your eye properly.
Unlike eyeglasses, contact lenses are considered medical devices that require a proper fitting.
Side-by-Side Comparison
|
Feature |
Eyeglass Prescription |
Contact Lens Prescription |
|---|---|---|
|
Used for eyeglasses |
✅ Yes |
❌ No |
|
Used for contact lenses |
❌ No |
✅ Yes |
|
Includes SPH |
✅ |
✅ |
|
Includes CYL & AXIS (if needed) |
✅ |
Sometimes |
|
Includes ADD (if needed) |
✅ |
Sometimes |
|
Includes PD |
Often |
Usually No |
|
Includes Base Curve (BC) |
❌ |
✅ |
|
Includes Diameter (DIA) |
❌ |
✅ |
|
Includes contact lens brand |
❌ |
✅ |
Why Can’t I Use My Contact Lens Prescription for Glasses?
Although some numbers may look similar, a contact lens prescription is missing information needed to manufacture eyeglass lenses.
For example:
- It usually doesn’t include your PD.
- Lens power may differ because contacts sit directly on your eye.
- Contact lens fitting measurements don’t apply to eyeglasses.
Using the wrong prescription could result in glasses that don’t provide the vision correction you expect.
Can My Eyeglass Prescription Be Used for Contact Lenses?
No.
A contact lens fitting requires additional measurements and an evaluation by your eye care provider to determine:
- Proper lens size
- Correct curvature
- Comfortable fit
- Eye health
- Appropriate contact lens brand
Even if your eyeglass prescription is current, you’ll still need a contact lens fitting before purchasing contact lenses.
How Can I Tell Which Prescription I Have?
Here are a few ways to identify your prescription.
You probably have an eyeglass prescription if:
- It lists SPH, CYL, AXIS, ADD, or Prism.
- It does not mention Base Curve (BC) or Diameter (DIA).
- It was given to you after a routine eye exam for glasses.
You probably have a contact lens prescription if:
- It lists BC (Base Curve).
- It lists DIA (Diameter).
- It includes a contact lens brand.
- It specifies replacement intervals such as daily or monthly lenses.
If you’re still unsure, your eye care provider can help identify which prescription you have.
What If I Wear Both Glasses and Contacts?
Many people have both an eyeglass prescription and a contact lens prescription.
This is completely normal.
For example:
- You might wear contact lenses during the day.
- You might switch to prescription glasses in the evening.
- You might alternate depending on work, sports, or travel.
If you wear both, make sure you’re using the correct prescription for the product you’re ordering.
What If I Accidentally Upload the Wrong Prescription?
Don’t worry.
Our team reviews every prescription order before production begins.
If the prescription appears to be incomplete, incorrect, or looks like a contact lens prescription, we’ll contact you before manufacturing your lenses.
This review process helps prevent unnecessary delays and ensures we have the correct information to complete your order.
Common Mistakes
Avoid these common mistakes when ordering prescription glasses:
- Uploading a contact lens prescription instead of an eyeglass prescription.
- Assuming the prescriptions are interchangeable.
- Forgetting to include your PD.
- Uploading an incomplete prescription.
- Using an expired prescription.
- Entering contact lens measurements (BC or DIA) into eyeglass prescription fields.
- Assuming lens powers are always identical between glasses and contacts.
- Ordering before confirming you have the correct prescription.
- Ignoring requests for clarification if our team contacts you.
- Waiting until after production begins to report an error.
Frequently Asked Questions
Can I use my contact lens prescription to order glasses?
Generally, no. You’ll need a current eyeglass prescription.
Why are the numbers different?
Contact lenses sit directly on your eyes, while eyeglasses sit in front of them. Because of this, the required measurements may differ.
What does BC mean?
BC stands for Base Curve, which describes the curvature of a contact lens. It is not used when making eyeglass lenses.
What does DIA mean?
DIA stands for Diameter, which measures the width of a contact lens. It is not part of an eyeglass prescription.
Why doesn’t my contact lens prescription include PD?
PD is used to position eyeglass lenses correctly inside a frame. Contact lenses move with your eyes, so this measurement usually isn’t required.
Can my eye doctor provide both prescriptions?
Yes. If you’ve had both a comprehensive eye exam and a contact lens fitting, your eye care provider can provide both prescriptions.
What if I only have a contact lens prescription?
Contact your eye care provider and ask for your eyeglass prescription before ordering glasses.
Can I wear contact lenses and prescription glasses?
Yes. Many people alternate between the two depending on their activities and preferences.
What if I’m unsure which prescription I have?
Our team is happy to help review your prescription before production begins. If we have any questions, we’ll contact you.
Does Choice Eyewear check my prescription?
Yes. Every prescription order is reviewed before manufacturing to help ensure the information is complete and accurate.
Key Takeaways
Although eyeglass prescriptions and contact lens prescriptions both correct your vision, they serve different purposes and are not generally interchangeable. Using the correct prescription helps ensure your glasses are made accurately and provide the best possible visual experience.
If you’re ever unsure which prescription you have, it’s always better to verify before placing your order. And if we notice anything that doesn’t look right, we’ll reach out before your lenses are manufactured.
Related Guides
- Understanding Your Eyeglass Prescription
- How to Measure Your Pupillary Distance (PD)
- How to Order Prescription Glasses
- Progressive vs. Single Vision Lenses
- Lens Options Explained
Need More Help?
Still unsure whether you have the correct prescription? Contact the Choice Eyewear team, and we’ll be happy to review your prescription and help you place your order with confidence.
