ClearlyContacts.ca Help Center
How Do I Read My Eyeglasses Prescription?
When ordering from ClearlyContacts.ca you must have a valid eyeglasses prescription from your eye doctor. Here are some helpful tips for how to read your prescription. Keep in mind, not all prescriptions will have these fields filled out.
Eyeglasses Prescription Example
Eyeglasses Rx Terms
|OD||Right Eye||Right eye parameters|
|OS||Left Eye||Left eye parameters|
|SPH or PWR||Sphere or Power||Measure of near or far sightedness||-12.00 to +6.00|
|CYL||Cylinder||Measure for astigmatism||-3.75 to +3.75|
|X||Axis||Direction of cylindrical lens||0° to 180°|
|ADD||Add Power||Additional plus power for near sightedness. Used for progressive and bifocal prescriptions.||1 to 4, or HIGH, MED, LOW|
|PRISM/BASE||Optical Prism||Measure to compensate for eye alignment problems||0.5 base up (BU)|
|PD||Pupillary Distance||Measure of distance between pupils||
Adults: 58mm to 70mm, Children: 41mm to 58mm
Tags: How do I enter my prescription, reading prescription, read my prescription, perscription, my prescription