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Reading Your Rx-Understanding that Prescription Jibberish

Understanding that Prescription Jibberish

-Look at the abbreviations OS and OD. OS stands for oculus sinister, a Latin phrase for the left eye. OD stands for oculus dextrus and means the right eye. In some instances, the notation OU will be included in the prescription. OU, which stands for ocular utrique, means that there is something in the prescription involving both eyes.

-See the numbers shown on the prescription. The further away from zero the number is, the worse the eyesight and therefore the more vision correction you need. If the number has a plus sign in front of it, this means you are farsighted, or can see distances but have trouble with your up-close vision. If the number has a minus sign in front of it, this means you are nearsighted, or can see up-close but have difficulty with your distance vision. The numbers represent diopters or a capital D, the unit that is used to measure the correction required.

-Decide whether you are nearsighted or farsighted according to your prescription. If the prescription you are given reads -1.00, this means you have one diopter of nearsightedness. This is not an extreme prescription. If the prescription reads -4.25, this means you have 4 1/4 diopters of nearsightedness. The second prescription would require a thicker lens than the first. Likewise, +1.00 would be a small degree of farsightedness and +5 would be a much stronger prescription.

Understand that some people are neither nearsighted nor farsighted. Take the prescription and observe your prescription. If you have astigmatism, your prescription will look different. There are three numbers on those prescriptions. The form for writing the numbers is S x C x Axis. The spherical portion of the prescription is noted by the letter S. This notes the degree of nearsightedness or farsightedness.

The C refers to the cylinder or astigmatism. The C can be a negative number or a positive number. The cylinder measures the degree of astigmatism that exists in diopters. A larger number indicates a greater degree of astigmatism.

Somewhere between 0 and 180 degrees is the axis. The axis discloses the orientation of the astigmatism or rather where the difference in curvature is taking place.