Contact Lens Prescriptions Explained

Contact Lens Prescriptions Explained

Contact Lens Prescriptions Explained

It may seem like gibberish but those numbers and abbreviations on your contact lens prescription are important. When ordering contact lenses online, you’ll need to have your prescription handy to ensure you’re getting the right lenses. Not only will the correct contact lens prescription enable you to see clearly, it will also mean the lenses you order actually fit your eyes for optimal comfort and safety. Confused by the jargon? Have no fear. Fresh Lens is here with our guide to understanding your contact lens prescription.

Breaking Down Your Contact Lens Rx

Contact Lens Prescriptions Explained

Most contact lens prescriptions contain the following abbreviations:

  • OD, OS and OU: OD is the right eye and OS is the left eye. OU means each eye and might be used if the measurement is the same for both peepers.

O.D. & O.S Contact Lens Prescription

  • SPH (or Power or PWR): The sphere or power is the measure of nearsightedness or farsightedness and tells the amount of correction needed in diopters. If there is a minus sign before the number, you’re nearsighted. A plus sign would mean you’re farsighted. The larger the number, the more correction needed.

SPH or Power OR PWR Contact Lens Prescription

  • BC: BC stands for base curve and is typically a number between 8 and 10. This refers to the curvature of the lens, which should complement the curvature of your cornea for comfort.

B.C Contact Lens Prescription

  • DIA: DIA or diameter is a number between 13 and 15 and is a measurement in millimeters of the lens width. This number is super important because the edge of the lens needs to rest in the correct place for comfort and to avoid irritation or abrasions.

DIA Contact Lens Prescription

  • Brand: This indicates the brand the optometrist fitted you for.

Brand Contact Lens Prescription

If you have astigmatism, your prescription will also contain the following:

  • Axis: The axis is shown in degrees between 0 and 180 and indicates the position of the astigmatism correction.

Axis Contact Lens Prescription

  • CYL: CYL stands for cylinder and measures the degree of correction needed for your astigmatism.

CYL Contact Lens Prescription

If you need bifocal or multifocal lens your prescription will note:

  • ADD – This means “add power” or “extra strength” and indicates the additional strength you’ll need to see up close.

ADD Contact Lens Prescription

Your prescription may also note the color of the lenses if you’re going for fancy colored contacts as well as an expiration date, which is usually one to two years after the fitting.

Can I Buy Contact Lenses Without a Prescription?

While it may seem convenient to forgo the trip to the eye doctor to get a prescription, it’s ill advised. By law, to purchase contact lenses in the U.S. you need a valid prescription from an eye care practitioner (either an optometrist of ophthalmologist). Why? Because contact lenses are considered medical devices and if they don’t fit right or aren’t made from approved materials, you won’t be able to see clearly and you run the risk of infection, abrasions or in rare cases, permanent damage to the eyes. When people buy contact lenses in Canada or the U.S. from Fresh Lens, we require a valid prescription. You can be rest assured your vision will be on point, the lenses will fit and your eyes will be comfortable.

What is a Contact Lens Fitting?

So now that we’ve explained the ins and outs of your contact lens prescription, are you ready to go get your eyes examined so you can order a batch of contacts online? Well, it’s important to note that the eye exam for contact lenses includes a few extra steps and your eyeglasses and contact lens prescriptions are different. So when you see your ophthalmologist or optometrist be sure to indicate you want a contact lens fitting as well.

Contact Lens Prescriptions Explained

After you navigate your way through the usual, “Which one is clearer? A or B?” and stare down that eye chart, the eye care professional will measure your cornea using an instrument called a keratometer and might break out the corneal topographer for an even more precise evaluation. The size of the pupil and iris may be measured too. They’ll then take a look at the surface of your eye and check out the contact lens’s fit with a trial pair and a biomicroscope. Once they’ve nailed down which contact lenses will work best for you, you’ll be given your prescription. Then you’ll be ready to take advantage of the ease of ordering contact lenses online in the U.S. and Canada, at Fresh Lens, of course.

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    Frequently Asked Questions.

    How do I order contact lenses?

    Ordering contact lenses through Fresh Lens is a simple process:

    Browse and Choose: Explore our extensive collection of contact lenses to find the perfect fit for your needs. Whether you're looking for daily, weekly, or monthly lenses, we have a wide range of options to suit your lifestyle.

    Enter Your Prescription: Have your prescription details ready? Great! Enter the necessary information during the ordering process. This ensures that you receive lenses tailored to your specific vision requirements.

    Add to Cart: Once you've input your prescription, add the selected contact lenses to your cart. Take your time to review your choices and ensure they align with your preferences and prescription needs.

    Checkout with Ease: Ready to proceed? Head to the checkout, where you'll provide your shipping details. Our user-friendly interface makes it a breeze to complete your purchase securely. Simply follow the prompts and finalize your order by making a seamless payment.

    Remember, it’s important to have a current prescription from your optometrist when ordering contact lenses. Stay safe and take care of your eyes! 👀

    How fast will I get my contact lenses?

    We understand how important it is to receive your contact lenses quickly and efficiently. At Fresh Lens, we offer several shipping options to ensure your order arrives as promptly as possible.

    For Canadian Orders:

    • Your contact lenses will be shipped via Xpresspost and typically take 3-5 business days to arrive from the date of your order. You'll receive a tracking number once your order ships, so you can follow its journey to your doorstep.

    For US Orders:

    • We provide three convenient shipping methods to cater to your needs:
    1. USPS Tracked Packet: Your lenses will arrive in 3-5 business days.
    2. Xpresspost USA: A faster option, with delivery in 2-3 business days.
    3. Next Day USA: For the quickest delivery, your lenses will arrive in 1-2 business days.

    Regardless of the method you choose, we’ll email you a tracking number once your order ships. Please note that while these are average shipping times, actual delivery may vary slightly. If your prescription is not in stock, it may take an additional 2 business days to order from the manufacturer.

    Choose Fresh Lens for reliable and swift delivery of your contact lenses!

    How can I renew my expired prescription?

    Renewing your expired prescription with Fresh Lens is quick and easy! We offer a free online tool that allows you to update your prescription in just 6 minutes (available for orders over $200).

    Here’s how it works:

    1. Take the Test Online: All you need is your phone, computer, and 10 feet of space. The test takes about 6 minutes to complete.
    2. Doctor Reviews Your Results: A licensed optometrist or ophthalmologist in your region will review and approve your results.
    3. Use Your Results: Access your updated prescription anytime through our online portal.


    • Convenient: Complete the test from the comfort of your home.
    • Accessible: Access your prescription anywhere, anytime.
    • Doctor Approved: All prescriptions are issued by licensed eye care professionals.

    <Renew My Rx Online>