If you are returning from the optometrist and having a hard time understanding your prescription, this article will teach you how to read your glasses prescription. An eyeglass prescription is a document written by an optometrist or ophthalmologist that specifies the values of the parameters necessary to make or dispense corrective lenses for the patient. The glasses prescription is typically given to the patient by his or her doctor at the end of the eye exam.
The glasses prescription has a variety of terms that will be explained below:
- OD This is a reference in Latin for right eye or “oculus dexter.” This is usually the first row in the prescription.
- OS This is a reference in Latin for left eye or “oculus sinister.” This is usually the second row in the prescription.
- Sphere A positive number indicates hyperopia (farsightedness) and a negative number indicates myopia (nearsightedness). It is usually the first column listed in the prescription.
- Cylinder This number refers to astigmatism. This is usually the second column listed in the prescription.
- Axis This number refers to the degree of the astigmatism and reveals the orientation of astigmatism. This is usually the third column listed in the prescription.
- PL or Plano Both PL or Plano can be used under the Sphere readings to indicate no refractive error (no hyperopia or myopia).
Example of a glasses prescription:
-1.25 +1.00 x 90
+3.00 +2.00 x 180
The first prescription means the person has 1.25 diopters of myopia (nearsightedness) with one diopter of astigmatism and an axis of 90 degrees in the right. eye.
- The second prescription means that the person has three diopters of hyperopia (farsightedness), two diopters of astigmatism and an axis of 180 degrees in the left eye.
- Remember to always consult your doctor if you have any other questions about your glasses prescription.
- The numbers on the prescription are measured in diopters, which measures the focusing power needed for the corrective lenses. The higher the numbers in either direction (positive or negative), the stronger the corrective lenses.