The eyeglasses prescription is usually recorded on paper which much likes a prescription for medication and contains a series of numbers and abbreviations. So to understand the eye prescription, you must know what those numbers and abbreviate words stands for.
In detail, the strength of the right is listed in Latin on optical prescriptions as O.D. shorted from Ocular Dexter. While the power of the left eyes usually marked as O.S (Ocular Sinister). Besides, sometimes, you can also find some eye prescription marked as DV which is the short for Distance Vision.
Then, we can often see there are minus sign (-) and plus sign (+) before the numbers of the SPH value. Please take it seriously. If there is no minus sign or plus sign before the SPH value, it has no meaning of the SPH value. In fact, the minus sign (-) stands for myopia (nearsightedness) while the plus sign (+) stands for hyperopia (farsightedness).
Furthermore, for people who suffer astigmatism, there also come to CYL and Axis next to the SPH. The Cylinder is the amount of power in your astigmatic correction while the Axis is the location of the cylinder in the lens, between zero and 180 degrees. The accuracy of the number is very important for a pair of suitable eyeglasses.
What’s more, you will also see PD on your prescription. It is stands for the pupillary distance which is the measurement in millimeters of the distance between your pupils.
At last, for people who need bifocal eyeglasses, there are must ADD or NV (near vision) on eye prescription. And the number must be always marked as a plus sign (+).
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