This is how you interpret your glasses prescription

H or OD – right eye V or OS – left eye Bino or OA – both eyes

Sphere (SF/SPH/PWR)

The sphere value indicates how strong the glasses are. In front of the value is a plus sign if you are farsighted, or a minus sign if you are nearsighted. Be careful with the sign when ordering. If the sign is missing, it should be considered a plus value. If it says plan(o) instead of a numerical value, it means +/-0, i.e. no strength.

Cylinder (CYL)

Corrects your astigmatism, or refractive error as it is also called. Always filled in as a negative value, minus (-). Should also always be specified together with an axis position.

Axis (A/AX)

Only filled in by you who have a value for cylinder. The axis position is given in degrees and describes the direction of the cylinder for correcting corneal astigmatism. It is required for the glasses to be properly adjusted. The axis value is always between 0° and 180°. NOTE – must always be included if there is a value for cylinder!

Addition (ADD)

Reading supplement for those who need it. To be filled in when ordering progressive glasses. The value is always positive and usually identical for both eyes. Therefore, it is sometimes specified only once. When ordering reading glasses, you must add the strength of sphere + add. Then fill in the total under “sphere”.

Pupillary distance (PD / MPD / PD/a)

PD stands for the distance between the center of each pupil to the center of the nose, measured in millimeters. Usually, the PD for the right and left eyes is specified separately, and is normally 25–38 mm. Sometimes a total value for PD is specified, which is then 50–80 mm. When ordering, divide this value by 2, i.e. PD 62 is specified as 31 (right) / 31 (left).

When you read, the eyes turn inward, which causes the distance between the pupils to decrease by a few millimeters. Therefore, PD/n (close) is indicated in many prescriptions. PD/n you use when ordering reading glasses. If you do not have a PD/n in your prescription, deduct 2 mm per eye from your distance PD.

Prism

Correction of strabismus. NOTE – we are not able to grind glass with a prism.

Correct vision

Visual acuity at a distance with correction (i.e. with glasses/lenses). This value is not specified when ordering.

Free vision

Visual acuity at a distance without correction (i.e. without glasses/lenses). This value is not specified when ordering.

For contact lens wearers: It is not possible to transfer the power of glasses directly to contact lenses, nor vice versa – from lens power to glasses. The reason is that the lenses sit directly on the cornea, while glasses sit some distance from the eyes. You should always seek the help of an optician to find the right contact lenses.

Source: MR SPEX

https://www.misterspex.se/c/rat/510