Deciphering Your Eye Prescription: OD vs OS Explained

Ever looked at your eye prescription and felt like you’re reading a mysterious code? Worry not! In this simple guide, we’ll unlock the meanings behind the abbreviations OD and OS, helping you understand your vision needs better. It’s crucial to know these details when ordering eyeglasses online to ensure that your new specs will help you see clearly and comfortably.


Understanding OD and OS

The terms OD and OS are short for the Latin phrases “oculus dexter” and “oculus sinister,” which translate to “right eye” and “left eye,” respectively. When you see OD and OS on your prescription, they’re simply indicating the vision correction for each eye. Here’s a breakdown of what you might find next to these abbreviations:

  • Sphere (SPH): This number shows the level of lens power, measured in diopters, needed to correct your vision. A negative value indicates myopia (nearsightedness), and a positive value suggests hyperopia (farsightedness).
  • Cylinder (CYL) & Axis: These values are related to astigmatism. The CYL number represents the lens power for astigmatism, and the Axis denotes its orientation.
  • Add: This number is relevant for those who need progressive lenses or bifocals, signifying the added magnifying power for reading.
  • Prism: This indicates the need for prismatic power to correct eye alignment issues, measured in prism diopters.

By familiarizing yourself with these terms, you gain a clearer understanding of your visual health and keep informed on what your eyes require.


Measuring Pupillary Distance

Another vital piece of information is your pupillary distance (PD), the space between the centers of your pupils. This measurement ensures that the lenses are positioned correctly in the frames. If you’re unsure of your PD, you can easily measure it at home or visit an eye care professional. For a step-by-step guide, check out our infographic on pupillary distance. Your comfort and clarity of vision are our priority, and getting the PD right is a crucial step in achieving that.


Next Steps: From Prescription to Perfect Pair

Now that you’ve decoded your prescription, you’re ready to find the perfect pair of glasses. Whether you’re looking for stylish frames, specialized lenses, or simply want to update your look, understanding your prescription is the first step to ensuring your glasses meet your needs.

Here are a few tips to help you on your way:

  • Review Your Prescription: Before making any selections, double-check your prescription details. Ensure that you’ve read and entered all information correctly, especially the OD and OS values.
  • Browse Frame Options: Choose frames that complement your face shape and personal style. We offer a diverse range of glasses frames for women and men, so you’ll find something that’s just right for you.
  • Select the Right Lenses: Depending on your prescription, you might benefit from single vision, bifocals, or progressive lenses. Always select lenses that cater to your specific vision needs.
  • Consider Lens Coatings: From anti-reflective coatings to UV protection, consider adding lens treatments that can protect your eyes and enhance your vision quality.

When you’re ready to order, we’re here to help every step of the way. Don’t hesitate to reach out if you have questions or need assistance. At Zenni Optical, our mission is to provide you with affordable, high-quality eyewear that perfectly fits both your vision needs and your lifestyle. Start exploring our collection today and experience the clear difference the right pair of glasses can make.


About the Author: Dr. Steven Liem, OD, FAAO

Dr. Steven Liem, O.D., F.A.A.O. is an optometrist based in Pasadena, California. After obtaining his doctorate from UC Berkeley’s School of Optometry, he completed his residency in Pediatrics, Vision Therapy & Rehabilitation and became a Fellow of the American Academy of Optometry. When he isn’t busy streaming or making Youtube videos about video games, Dr. Liem aims to broaden accessibility to vision health through his involvement in optometric industry and tech.