Sphere (D/dpt./S/SPH/PWR) refers to the refractive power of the contact lens. The unit of measurement for spherical power is a diopter or D. Generally, the spherical power of a lens is indicated with a plus sign (+) for hyperopia and a minus sign (-) for myopia.

The cylinder value (CYL) is required for the production of contact lenses for astigmatism. It is a negative value that corrects the corneal curvature.

Axis (A/ACH/AXIS/AX) is needed in astigmatism as a supplement to the cylinder. It describes the exact position of the curvature on the cornea and is given in a range of 0°-180°. 0° is also written as 180°. 90° stands for the vertical position, 180° for the horizontal meridian.

Sphere (D/dpt./S/SPH/PWR) refers to the refractive power of the contact lens. The unit of measurement for spherical power is a diopter or D. Generally, the spherical power of a lens is indicated with a plus sign (+) for hyperopia and a minus sign (-) for myopia.

ADD is the difference between the dioptric value for distance vision and the dioptric value for near vision. Values up to +1.25 are considered low, up to +2.00 are considered average and up to +3.00 are considered high.