How do I interpret my glasses prescription?

After the ophthalmological examination, you will receive an ophthalmological report from the doctor. If optical correction is required, along with the finding you will also receive a prescription for making glasses, with which you go to the optician.

Since the glasses prescription contains a lot of labels and abbreviations in the Latin language, there is a possibility that you will not understand everything written. Therefore, we bring you an interpretation of the basic terms that can be found in the prescription for glasses.

Eye exam

Prescription for glasses – basic concepts

D stands for diopter. In front of this mark is a number that shows your diopter (the higher the number, the higher the diopter). If there is a plus sign in front of the number, it means that you are farsighted, that is. to see less close up. If there is a minus in front of the number, you are short-sighted, that is. you see less at a distance.

OD and OS are basic abbreviations that indicate which eye is involved. OD (oculus dexter) is the designation for the right eye, while OS (oculus sinister) represents the left eye. OU (oculus uterque) means both eyes.

Spherical and cylindrical diopters

• SPH – designation for the sphere, which means that the prescribed correction for nearsightedness or farsightedness is “round” and equal in all meridians. The higher the number, the higher the diopter.

• CYL – designation for the cylinder that people with astigmatism (irregularly curved cornea) have. This number indicates the amount of astigmatism in diopters and can be positive or negative, and the higher it is, the greater the curvature of the cornea.

• AX AXIS represents the angle of the cylinder and ranges between 0 and 180 degrees. This number indicates the angle of the cylinder that is necessary for clear vision.

PD (pupillary distance) is the designation for the distance between the pupils in millimeters. Pupil spacing for near is always smaller than pupil spacing for distance correction.

“PLAN” – If you come across this mark in the results, it means that you do not have dioptre in that eye. It is possible that the diopter exists only in one eye, so this mark is written in the other eye.

Senile farsightedness

If you have presbyopia, the so-called elderly dioptre for near vision, your prescription for glasses will also include a certain supplement that determines the size of the correction for clear near vision.

Writing a prescription for glasses

ADD – symbol for addition, ie. an allowance that usually ranges between 0.50 and 3.50D and is the same in most cases for both eyes. This number always has a plus sign and shows the dioptre that is added to the prescription dioptre for the distance, ie. for the lower half of bifocal or multifocal (progressive) lenses to correct presbyopia.

If you have diopters for both distance and near, you need two pairs of glasses.