How Do I Read My Prescription?

Knowing and understanding your prescription is essential when planning on purchasing a new pair of glasses. That is why we have put this little Online Prescription Glasses Guide together. Keep in mind that if you're not completely comfortable filling your glasses prescription out online, you can just send us your prescription by fax or e-mail and our optical experts will fill it out for you.

Every doctor writes their prescription a bit differently, so here are a few examples of what your prescription might look like:

Prescription Values explanations

OD - short for oculus dextrous which really means your right eye
OS - short for oculus sinister which really means your left eye
SPH - short for sphere - the main part of your prescription. It indicates the strength of your prescription in diopter.
CYL - short for cylinder - which indicates the strength of your astigmatism, if you have one.
AXIS - the rotation of the cylindrical lens (CYL) that runs on a plane of 1-180 degrees.
PL - short for plano - which means there is no vision correction needed.

Your prescription's numerical values will come with either a plus (+) or a minus (-) sign in the SPH as well as the CYL and ADD. Pay close attention to those signs. Mixing up the symbols will affect how you see through the lens. Now that you understand the abbreviations, let's jump right into your prescription.

SPHERE - indicates the strength of your prescription in 0.25 increments.

Nearsighted prescriptions (myopia), for people who have problems seeing afar, will usually have a minus (-) sign in the sphere; Farsighted prescriptions (hyperopia), for people who have problems seeing up close, will usually have a plus (+) sign in the sphere.

This sign is quite common and looks like an 8 on its side but it stands for 'infinity'. Sometimes 'PL' is used instead. To fill your glasses prescription online you can scroll down and select None, Plano 00, or 00.

Your doctor may also write your SPH or CYL as +150, which is equal to +1.50.

CYLINDER - This figure is required if you have something called 'astigmatism' - an optical condition that can make your vision blurry.

Not all prescriptions have a cylinder and some prescriptions have a cylinder in only one eye. If you don't have astigmatism correction, your doctor may leave the field blank but they might also put SPH, 00, Plano, or DS. All of these mean you have no correction for astigmatism in one or both eyes.

To fill your glasses prescription online you can scroll down and select None, Plano 00, or 00.

**Your prescription's numerical values will come with either a plus (+) or a minus (-) sign in the SPH as well as the CYL and ADD. Pay close attention to those signs! Mixing up the symbols will affect how you see through the lens.

AXIS - The Cylinder (CYL) and Axis are always provided together because the Axis will tell us at what degree to put the cylinder lens. Axis should be from 1-180 degrees and will always be a whole number. If your Axis is written as "6", it can be entered as 06 or 006.

ADD - The additional value or ADD is commonly used for bifocal or progressive lenses as well as for reading glasses.

Your doctor may write your ADD in the near vision (N.V.) or ADD section - like the prescription above - indicating on the side that this is the ADD. Sometimes your doctor will write the ADD once - it will be equal for both eyes and other times each eye will have their own ADD value - like above.

If your prescription has an ADD and you only want single vision distance glasses - simply leave the ADD off of your prescription when ordering. If you're buying reading glasses, be sure to leave the ADD on your prescription - we need it to manufacture your reading glasses.

PD - Your pupil distance is important when we are creating lenses to match your prescription because we need the optical center of each lens to align with your pupils!

The average PD is 62mm and most people fall within the 54mm to 74mm range. If you measured your own PD and your number is outside this range - we recommend remeasuring, do not guess your own pupil distance.

Your PD is written a few different ways. You may see it written like:
63
32/32
33/31
30.5/33.5
63/60

If your PD is written as 63 - simply insert it as 63. If your PD is written as 32/32, you can add the two together and insert 64 or you can check the box that reads "I have 2 numbers for my PD" and insert your PD as 32/32.

If your PD is written as 33/31 or 30.5/33.5 - the measurements from the center of your nose to the pupil on either eye is not equal and you should check the box that reads "I have 2 numbers for my PD" and insert your PD as written on your prescription. Do not add the numbers together.

Your PD may also be written like 63/60 - which means 63 your PD for your distance vision and 60 is the PD for your near vision. Your PD for near vision will usually be 3mm less than your distance vision PD.

**If you're ordering progressive or bifocal lenses - you must have your PD before ordering!