Contact Lens Prescription

Valid prescription required

You hereby certify that you hold a valid prescription for the contact lenses you wish to order. This means that your prescription was made within 12 months from the date of purchase and that the prescription has been dispensed by a qualified optometrist or contact lens fitter (hereafter referred to as a practitioner). We reserve the right to verify such detail with your practitioner.

What is a contact lens prescription?

A contact lens prescription contains all the specifications of your contact lens and lets you know which type of lenses you require. It's essential to note that a contact lens prescription is not the same as a glasses prescription. If you're currently wearing glasses and want to try out contact lenses, its better to first go for a contact lens fitting to find out which brand of lenses are best for you.

Where can I find my prescription?

Your prescription can be found on the piece of paper given to you by your optician after your contact lens fitting or on the end or side of your contact lenses box, on the blister pack containing your lenses.

What's the difference between a glasses prescription and a contact lens prescription?

There are a few differences notable between a contact lens and a glasses prescription. Your glasses are usually 12 mm away, while contact lenses sit directly on your eye’s surface. This difference may seem very small , but it greatly affects the corrective power of your prescription.

Another difference between glasses and contacts prescriptions is the extra specifications needed for contact lenses. Contacts need to fit your eyes comfortably to work effectively, so your optometrist will measure the curvature and width of your eye.

What Do the Letters in Your Contact Prescription Mean?

OD and OS: Along the top, or side, of any prescription you will find the letters OD and OS. Wouldn't it be easier if they just wrote L and R for Left and Right? Well, OD is short for the Latin term for Right Eye: "oculus dexter", and OS comes from the Latin for Left eye "oculus sinister." So just remember OD is your RIGHT eye and OS is your LEFT eye. Occasionally you may see the letters OU on your prescription, which is short for "oculus uterque" or EACH EYE, meaning the same measurement applies to both.

PWR: PWR refers to refractive power. Sometimes this may also be called SPH (sphere.) This is the amount of correction, measured in diopters (an optical unit of measurement,) that is needed to bring your vision to 20/20 - or as close as possible. If this number is preceded by a minus sign, then you are nearsighted (you have myopia.) If there is a plus sign before the number, you are farsighted (you have hyperopia.) The further the number is from zero, the stronger your prescription. It is common to have a different prescription in each eye.

BC: Base Curve refers to the back curvature of the contact lens, which needs to fit seamlessly against the surface of your eye. The optometrist uses this number to ensure the size of your contacts perfectly integrates with the size of your cornea. The base curve is usually measured in millimeters between 8 and 10. If your prescription does not include a base curve, it's most likely because the brand of your lenses only comes in one base curve.

DIA: Diameter is the distance across the surface of the contact lens, measured in millimeters. This number is usually between 13 and 15 and determines where on your eye the contact lens will sit. If this measurement isn't correct the contact lens will be uncomfortable and may scratch your eye.

How Long Is a Contact Prescription Good For?

Most contact lens prescriptions come with an expiration date between one and two years from the date of your last exam. Once that prescription expires, it's time to head back to the eye doctor for a check-up and to make sure nothing has changed. Our eyesight changes as we get older, so regular check-ins with your eye doctor allow you to protect the health of your eyes with the most up-to-date prescription.