Posted by Alena on 9th Sep 2025
How To Read Your Prescription
How? Tips on Reading Your Prescription
Reading the corrective prescription that your eye doctor gives you is pretty straight forward. A sample eye prescription is below, with an explanation of each of the fields.
- OD (Oculus Dexter): Right eye prescription
- OS (Oculus Sinister): Left eye prescription
- Sphere: This number indicates the lens power, measured in diopters (D), needed to correct your vision. If the number is negative (e.g., -2.00), it indicates correction for nearsightedness (myopia), meaning you have difficulty seeing distant objects clearly. If the number is positive (e.g., +2.00), it indicates correction for farsightedness (hyperopia), meaning you have difficulty seeing close objects clearly.
- Cylinder: Refers to the lens power needed to correct astigmatism, which is a common condition where the cornea or lens of the eye has an irregular shape.
- Axis: Specifies the orientation of the astigmatism correction in degrees, ranging from 0 to 180.
- Prism: Refers to the amount of prism correction required to address vertical misalignments in the eyes, such as vertical heterophoria or strabismus. Prism correction helps align the eyes properly, ensuring that they work together to produce a unified clear image.
- Add: Refers to the additional lens power needed for reading or close-up tasks, typically for individuals with presbyopia, a condition that commonly occurs with aging and affects near vision.
If you want to further understand you eye prescription, check out the video below by Dr. Joseph Allen, OD FAAO.
Source:
https://www.reddit.com/r/glasses/comments/1ggqnhe/blog_series_geek_chic_eyewear_indepth_eyewear/