Example of what your prescription may look like.

1. Sphere (SPH):

  • Indicates the main lens power to correct nearsightedness (negative values) or farsightedness (positive values).
  • Written in diopters (D); the higher the number, the stronger the prescription.

2. Cylinder (CYL):

  • Addresses astigmatism, a condition caused by irregular cornea or lens shape.
  • Positive or negative values denote the degree of astigmatism correction needed.

3. Axis:

  • Specifies the angle (in degrees) for astigmatism correction.
  • Ranges from 0 to 180; helps align the cylindrical power correctly.

4. Add:

  • Applies to multifocal prescriptions (bifocals, progressives) for additional power needed for reading or close work.
  • Written as a positive value.

5. Prism:

  • Indicates the amount of prismatic power required to correct eye alignment issues.
  • May be present for conditions like strabismus.

6. Base:

  • Corresponds to the base direction of the prism (up, down, in, out).

7. Pupillary Distance (PD):

  • Measurement between the centers of your pupils.
  • Ensures proper alignment of the optical center of the lenses with your eyes.

8. Lens Material and Coating:

  • Specifies the type of material for your lenses (e.g., high-index, polycarbonate).
  • Coatings may include anti-reflective, anti-scratch, or UV protection.

Example of the information provided on a prescription.

This example will help you better understand the information provided to you on your prescription.

Sample Prescription

  • OD (Right Eye): -2.00 -1.25 x 180
  • OS (Left Eye): -1.75 -1.50 x 90
  • Add: +2.25
  • PD: 64

Understanding the Sample:

  • Right eye has myopia (nearsightedness) of -2.00 diopters with astigmatism of -1.25 at an axis of 180 degrees.
  • Left eye has myopia of -1.75 with astigmatism of -1.50 at an axis of 90 degrees.
  • Additional power for reading (+2.25) is included.
  • Pupillary distance is 64.