Understanding all of the numbers, words and symbols can be challenging for some. If there is nothing written in one of the columns or boxes, just leave them blank. It is not recommended to write on or alter your written prescription. Don’t hesitate to ask your eyecare professional to educate you in regards to your prescription.

OD—Right eye. Translated from Latin to English it means ocular dexter.

OS—Left eye. Translated from Latin to English it means ocular sinister.

Sphere—Prescribed power for an eye with a cornea that is sphere.

Sph—Abbreviation for sphere.

Cylinder—Prescribed power for an eye with a cornea that is not sphere.

Cyl—Abbreviation for cylinder.

Axis—The degree on which the astigmatic lens is placed. This ranges from 1-180.

Add—Prescribed magnification for bifocals, multi-focals and progressive addition lenses.

Prism—Prescribed prism brings the light to the eye by bending it.

Slab Off—Prescribed for bifocal wearers who experience double vision when reading.

Base Curve—The curve of the outside of the lens.

D or Diopter—A number value of the strength of the lens.

SV—Single vision prescription with only one focal length.

DV—Distance vision prescription for seeing at a distance.

RV—Reading vision prescription for seeing up close.

NV—Near vision prescription for seeing up close.

OU—Both Eyes.

Plano—No prescribed prescription.

Balance-Same or similar prescription for and eye that does not see.

PD—Pupillary Distance.

Examples of Eyeglass Prescriptions

Another Way To Write It
R: -1.50 –.075 x 090 2▲Down
L: -1.00 sphere

Add +1.50 ou

Sphere
The sphere can be written in plus + or minus –. Plus for nearsighted and minus for farsighted. The numbers can range from 0.25 to –16.00 and even higher. Sphere powers are prescribed in quarter (0.25) increments. In the examples above the right eye is minus 1.50 sphere and the left is minus 1.00 sphere.

Cylinder

When the shape of your cornea is non-sphere, a second correction needs to be prescribed. If there are numbers written in the axis column, there must be an Cylinder written in as well. The cylinder can be written in plus + or minus –. This depends on the equipment that the doctor examined your eyes with. Plus or minus symbols do not affect the prescription. The numbers can range from 0.25 to –4.00 and even higher. Cylinder powers are prescribed in quarter (0.25) increments. In the examples above the right eye is minus 0.75 Cyl.

Axis

Patients with astigmatism will have a cylinder correction. If there are numbers written in the Cyl column, there must be an axis written in as well. The axis numbers (degrees) range from 1-180. In the examples above the right eye axis is 090.

Add

The add power is the prescribed power for magnification. Generally speaking the add powers are the same for both eyes. There are times when the numbers will be different. The numbers range from +0.50 to+4.00 and even higher. Add powers are prescribed in quarter (0.25) increments. In the examples above the add power is +1.50 for both eyes.

PRISM

Patients with muscular imbalances, medical disorders, lazy eyes and other brain related conditions require prescribed prism. The numbers range from 0.25 to 6.00 and even higher. The direction of the prism can be up, down, in or out and/or a combination of these. Prism powers are prescribed in half (0.50) increments. In the examples above the right prism is 2 Diopters base down.