Your prescription can be measured by an optometrist (OD) or ophthalmologist (MD), but the information belongs to you and you should leave the doctor’s office with a copy of your glasses prescription. The glasses prescription can be used on any kind of eyeglasses; your glasses prescription is not restricted to glasses that may be recommended by the doctor. Also, be sure to ask the doctor to measure your pupil distance and write that down on the eyeglasses prescription as well. If you have your eyeglasses prescription with your pupil distance when you leave your eye doctor’s office, then you can buy glasses with that prescription at any eyeglasses store.
We strongly recommend that you fax your glasses prescription to us. We can read your eyeglasses prescription and then help find the best prescription eye glasses lens for you. For multifocal orders, we require that you fax your prescription to us.
Reading Your Prescription
Eyeglasses prescriptions have a certain format that is typically followed. The first line of your glasses prescription is always for the right eye, sometimes designated the OD. The second line is for the left eye, sometimes designated OS. The glasses prescription for each eye is divided into Sphere, Cylinder, and Axis values. It is common to have no values for any one of these, in which case you might see the letters PL or plano, or to have values for all of these. Sometimes the eyeglasses prescription may say OU which means both eyes.
Multifocal Eyeglasses Prescription
If your prescription is for bifocals or trifocals of progressive lenses, there may be additional information on the prescription that says for example Add +2.50. This is important information if you are ordering reading or multifocal lenses. The numbers are expressed in diopters (a universal value system) that tells the power of the lens. On a prescription for multifocal glasses lenses, you will see information designated as add power. Your add power is simply the magnification that is added to your sphere value for distance vision, in order to create a field of view for reading. For example, if your sphere value for distance viewing is 3.00, and your add power is +2.00, then your near vision correction is 1.00. Or, if your sphere value for distance viewing is +1.00 and your add power is +2.00, then your near vision correction is +3.00.
Pupil Distance PD
An accurate PD is a required measurement in order to make prescription glasses, and you cannot purchase from Eyeglasses.com without one. Your PD is the distance in millimeters between your pupils (the centers of your eyes). Your adult PD never changes, and it averages 60 millimeters (mm) for women, and 64 mm for men. Sometimes your eye doctor will write your PD for each eye (for example 33/34, called a monocular pd). Or, the eye doctor may write the PD as 67/64. This means that your PD for distance vision (or DPD) is 67, and for near vision (or NPD, for reading eyeglasses or multifocal lenses) it is 64. Your near vision PD is almost always 3mm less than your distance vision PD.