How to Read Your Eyeglasses Prescription

O.D (oculus dextrus) is for your right eye and O.S (oculus sinister) is for your left eye.

The “sphere” column indicates how near-sighted or far-sighted you are. A minus sign in the sphere column means that you are near-sighted and a plus sign means that you are far-sighted.

If you have astigmatism, your cornea is shaped like the back of a spoon, curved more on one side that the other. The “cylinder” column refers to the measurable degree of astigmatism of your central cornea. The orientation of the spoon shape can differ from person to person, for instance, like a spoon standing on the end or on it’s side.

The “axis” column describes the orientation in the degrees from horizontal.

Bifocal prescriptions are indicated with the number such as “+1.50 add”. This number, when added on the sphere column of the prescription, gives the strength of the near-vision part of the bifocal lens.

In the interest of your better Eye Health, from the practice of: 


(Hons. BSc, MSc, O.D., F.I.O.S)

6633 Hwy 7 at 9th Line

Markham, Ontario

905-471-EYES (3937)


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