Understanding OS and OD in Optometry
- BY Dr. Steven Liem
- IN Eye Health
Photo by Ksenia Chernaya
If you’ve ever looked at a prescription for glasses or contact lenses, you might have been puzzled by the terms OS and OD. These abbreviations are actually Latin terms and are part of the language of optometry. In this post, we will demystify these common acronyms and explain their significance in your vision correction journey.
Decoding the Acronyms
OD stands for “oculus dexter,” which translates to right eye, while OS signifies “oculus sinister,” or left eye. These abbreviations help your eye care provider indicate which eye a particular prescription is for, ensuring accurate vision correction. These terms are a crucial part of your glasses or contact lens prescription, and understanding them can provide valuable insight into your eye health and correction needs.
Reading Your Prescription
Photo by Ksenia Chernaya
Your prescription will typically list several values under each of these terms. These values include:
- Sphere (SPH): This indicates the amount of lens power, measured in diopters, needed to correct nearsightedness or farsightedness.
- Cylinder (CYL): This value corrects astigmatism and shows how much lens power is needed to correct the distorted vision caused by the irregularly shaped cornea or lens.
- Axis: This is a number, in degrees, that works in conjunction with the CYL value to indicate the orientation of the astigmatism.
Understanding these values can help you make informed decisions about your vision correction options, whether that’s progressive lenses or classic frames.
The Importance of Regular Eye Examinations
Regular eye examinations are crucial for maintaining good eye health. Not only do they provide an updated prescription for your vision correction needs, but they also allow your eye care provider to detect early signs of eye diseases such as glaucoma or macular degeneration. Armed with the knowledge of what OD and OS mean, you can actively participate in your eye care and understand more about your vision prescription.
