how to read glasses prescription

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 put together this prescription glasses guide.

Prescription terms

Plus & Minus

(+ & -)
A plus (+) sign next to the number refers to farsightedness correction.

A minus (-) is used to correct nearsightedness. prescription example plus and minus

Right eye & Left eye

(OD, OS & OU)
Right eye & Left eye - OD is short for oculus dextrous which means your right eye, OS is short for oculus sinister which means your left eye.

OU - short for oculus uterque which means the same values for both eyes prescription example right and left eye

Distance vision & Near vision

(D.V & N.V)
Distance Vision - DV is the portion of your prescription which corrects your ability to see things far away.

Near Vision - NV means your prescription is for reading only. prescription example distance and near vision


Measured in diopters, the number under this header refers to the lens power necessary for each eye. A minus (-) is used to correct nearsightedness. A plus (+) sign next to the number refers to farsightedness correction. prescription example sphere


The lens power (also diopters) used to correct astigmatism. If you have no astigmatism or very slight one, nothing will appear under this column. Just like with Sphere, minus is used to indicate lens power for nearsighted astigmatism, plus is for farsighted astigmatism. prescription example cylinder


Like Cylinder, this only applies to astigmatism prescriptions. The numbers under this column refer to angle degrees (1 to 180) and not diopters. If your prescription includes Cylinder lens power, it must include Axis as well. prescription example axis


Only used for multifocal (progressive/bifocal) lenses. It refers to the added magnifying power applied to the bottom of the lens in multifocal lenses. PAL is used in some cases by eye doctors when the addition for progressive lenses is different compared to bifocals. prescription example addition

Pupillary distance

The distance between your pupils in millimeters. If your prescription does not include a PD, please leave it at 62 for single vision & progressives. For bifocals and reading glasses, please provide the Near PD when applicable, otherwise you can leave it at 59. You can also measure it manually.

prescription example pupillary distance

Two PD Numbers

If your PD has 2 numbers (33/31 for example), the numbers indicate the distance between the center of each pupil to the bridge of your nose. The first number is always for the right eye, the second is for the left eye.

prescription example pupillary distance


Means blindness in one eye. In this case put the same values for Both eyes (OD & OS). prescription example balance


The prismatic power needed to compensate for eye alignment issues (double vision or lazy eye). Caused by muscular imbalance. The prism Rx will have two values: PRISM & BASE - The base can go Up, Down, In, or Out. If there is a prism, it must have a base as well! prescription example prism

Plano, DS

None, no values; You can have this value written in the sphere field, and still have cylinder & axis values, and vice versa. prescription example plano and DS
Dr. Richard Williams, Jr
1234 Lower St. Bronx, NY USA

How to send a prescription

If you're still not completely comfortable filling out your glasses prescription online, you can easily send us your prescription.
Watch the video below to see how it's done.
Watch the Video

Prescription types

Distance (single-vision)
This lens helps you see details at a distance. It is usually indicated by a (-) next to the numbers under the “sphere” category of your prescription.
Reading (near-vision)
This lens is intended for seeing details at a close distance. Most commonly used for reading. It is usually indicated by a (+) next to the numbers under the “sphere” category of your prescription.
Progressive/Bifocal (multifocals)
Multifocal lenses include multiple lens powers for a number of viewing distances. It is indicated in the prescription by the ADD power value, needed for reading.
Contact lenses
Only prescription specifically for contact lenses can be used to order contacts, as the values vary from eyeglasses prescriptions.
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Can SV lenses have a positive power?
Yes, they usually come in (-) power, but can have a (+) value as well.
What are "No lined Bifocals"?
No lined bifocals is usually used to describe Progressive lenses, that have no visible line dividing the distance & reading portions and provides 3 visual fields - distance, intermediate, & near.
Can my prescription be used for all types of lenses?
Depends on the RX the dr. Provided.
If the RX is for progressives or bifocals All other types of lenses offered can be produced.
Otherwise it can be used specifically for what it was subscribed.
What does it mean if I have 'intermediate' indicated in my prescription?
This means that this will be your additional power for intermediate range (computer/office distance) and not your full reading addition.