Eyeglass prescription - how to read it?
A prescription for glasses is a document that we receive after an eye examination by a specialist. It contains information about our vision defect and the parameters of the spectacle lenses that we need to improve the quality of vision.
Your glasses prescription consists of several elements, which may vary depending on the type of vision defect and correction. Here are the most important ones:
OP and OL – represent the right eye and the left eye.
DAL and NEAR – indicate whether we need correction for distance vision (Distance) or near vision (Near). The values in this column are expressed in diopters (D) and can be positive (+) or negative (-).
Sphere (SPH) – gives the power of a spherical lens, i.e. one that corrects nearsightedness or farsightedness.
Cylinder (CYL) – gives the power of a cylindrical lens, i.e. one that corrects astigmatism. If we do not have astigmatism, this field will be empty or will have a value of 0.
Axis (AXS) - gives the cylinder direction, or orientation of the cylindrical lens on the eye. This is a number from 0 to 180 degrees.
Addition – gives the additional power of the lens for near vision, which is needed by people with presbyopia. This is a positive value, added to the spherical power for near vision.
PD – stands for pupillary distance, which is the distance between the pupil centers of both eyes. This is an important parameter for the correct fit of spectacle frames and lenses.
Prism and base – relate to correcting the convergence or divergence of the eyes. The prism gives the amount of deviation in diopters, and the base gives the direction of the prism in degrees.
OP and OL – represent the right eye and the left eye.
DAL and NEAR – indicate whether we need correction for distance vision (Distance) or near vision (Near). The values in this column are expressed in diopters (D) and can be positive (+) or negative (-).
Sphere (SPH) – gives the power of a spherical lens, i.e. one that corrects nearsightedness or farsightedness.
Cylinder (CYL) – gives the power of a cylindrical lens, i.e. one that corrects astigmatism. If we do not have astigmatism, this field will be empty or will have a value of 0.
Axis (AXS) - gives the cylinder direction, or orientation of the cylindrical lens on the eye. This is a number from 0 to 180 degrees.
Addition – gives the additional power of the lens for near vision, which is needed by people with presbyopia. This is a positive value, added to the spherical power for near vision.
PD – stands for pupillary distance, which is the distance between the pupil centers of both eyes. This is an important parameter for the correct fit of spectacle frames and lenses.
Prism and base – relate to correcting the convergence or divergence of the eyes. The prism gives the amount of deviation in diopters, and the base gives the direction of the prism in degrees.
