How to Read Your Prescription

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Get a prescription paper written specifically for eyeglasses.

Note: The prescription for contacts CANNOT be used for eyeglasses.

Let’s take the following data as an exmaple:

	SPH	CYL	Axis	ADD	Prism	Base
R (OD)	+1.00	-0.50	179	+1.50	2	Up
L (OS)	-0.50	-1.25	003	+1.50	2	Down
PD 64 – OR – R 32 / L 32

 

OD	Right eye, latin for Oculus Dexter
OS	Left eye, latin for Oculus Sinister
OU	Both eye, latin for Oculus Uterque
SPH	Abbr. of Sphere, the degree of correction, it corrects your near or farsightedness.
CYL	Abbr. of Cylinder, it corrects your astigmatism, it will be 0 if you don’t have astigmatism
Axis	It indicates the orientation of astigmatism, measured in degrees from 1 to 180. It must follow with CYL. NO CYL, NO AXIS
ADD or NV	Addition or Near Vision, it is calculated for getting the correction for reading or near vision, it can be used for bifocal or multifocal progressive glasses.
Prism	Prismatic value, it is needed to compensate for any alignment problems in your eyes.
Base	The direction of a prism. There are 4 directions, up, down, in, out.
PD	Pupillary Distance. It’s the distance in millimeters between the center of one pupil to the center of the other. How to measure my PD?

Now that you know what these terms mean, you know how to read a glasses prescription, which is the most important part of learning how to buy prescription glasses online.

Now you can shop online.

How to measure the segment height for progressive no line bifocals:

How to measure segment height for line flat top bifocal lenses:

How to measure Pupillary Distance: