OD vs. OS: What do they mean?

Introduction

The Latin words for the two eyes are shortened to OD & OS, which stand for “right eye” and “left eye,” respectively.

But the tale doesn’t end there! If you found your way here to learn about OS and OD meaning, chances are you looked at your vision prescription & were a little confused by all those numbers and letters. Do you want to know the OS and OD meaning in detail? You are not alone, so don’t worry.

Continue reading to learn more about the significance of common abbreviations in addition to OS meaning and OD meaning. You can also read our comprehensive tutorial on how to interpret prescriptions for eyes.

Which of the Eyes is OS vs. OD

Let’s start by sorting through these eye acronyms and understanding what they mean.

1. OD meaning

OD is short for “right eye.” Since the Latin term for “right eye,” oculus dexter, is short for “right eye,” OD is the standard acronym for the right eye. Physicians may refer to the right eye simply as “RE” or “right” at times.

2. OS meaning

After understanding the OD meaning, let’s go on to the OS. The acronym OS stands for “left eye.” The Latin term for “left eye,” oculus sinister, is shortened to OS, which is the conventional acronym for the left eye. Regarding “left eye,” some physicians may simply write “left” or use LE.

3. OU meaning

Unexpectedly! Another acronym for eyes that you may notice on the prescription is this one. The Latin term for “both eyes,” oculus uterque, is shortened to OU.

Glossary of Terms and Abbreviations Used in Eyeglass Prescription

The eye prescription will undoubtedly contain a number of other unusual acronyms alongside OD & OS. The terminology that is frequently used and that you may come across when reviewing your prescription for your glasses is listed in this helpful list.

1. SPH

SPH is short for “sphere.” When farsightedness, nearsightedness, or both require vision correction, this acronym is employed. The power of the lens required to rectify it is indicated by the number this abbreviation displays.

You can be classified as nearsighted or farsighted based on whether the number associated with this phrase is negative (shown by a – sign) or positive (shown by a + sign). Prescriptions with both negative and positive numbers indicate that you require correction of vision for both near and farsightedness.

2. CYL

“Cylinder” (CYL) is an abbreviation for astigmatism. If you need to adjust for astigmatism, you only get a number starting CYL. The power of the lens required to correct astigmatism is indicated by CYL values, which can be either negative or positive. Astigmatism increases with increasing numbers.

3. Axis

The degree of astigmatism in the eye’s cornea is indicated by the term “axis,” which is expressed in degrees. Numbers in the AXIS and CYL columns of the prescription indicate if you are astigmatic.

4. Add

“Add” describes the additional magnification (if any) placed at the base of a progressive or multifocal lens, which is most frequently used to treat presbyopia.

5. BO, BI, BD, or BU

A column labeled “prism” or “base” may be part of your recipe. If you require an adjustment for misaligned eyes, these are included in the prescription you receive. Either “out” or “in,” or “down” or “up,” will be the basic value of a prism adjustment. BO, BI, BD, or BU are some examples of acronyms you may encounter. In addition, you will notice that the base number has a matching prism power.

6. PD

Pupillary distance, or PD for short, is a measurement of how far apart the pupils of your eyes are from one another. If this figure is missing from your prescription, try measuring the pupillary distance manually with our virtual tool.

For additional information on determining pupillary distance, read this informative article.

OS and OD meaning on a prescription for vision

The format of a vision prescription typically resembles a chart or table, with the words of the columns being along the top and the OD & OS in the rows located down the side. This is how it will appear.

Common Abbreviations for Lens Types

Your prescription may contain acronyms that indicate which of the different kinds of lenses your doctor feels you require. We are mindful of how many perplexing letters there are! We’re almost done, so keep going.

1. SV

“Single vision” is referred to by the acronym “SV.” It follows that this lens has a single prescription.

2. BF

For “bifocal,” use BF. The top of a bifocal lens is designed to view things at some distance, and the bottom is for near objects. These two unique prescriptions are found on bifocal lenses. There is a line that clearly distinguishes these two regions on the lens.

3. TF

“Trifocal” is what TF stands for. Similar to a bifocal lens, a trifocal lens adjusts for 3 different fields of vision: near (around the bottom of the lens), intermediate (at the middle), and distance (at its top). The three distinct regions of the lens are clearly defined by a line.

4. PAL or PL

Progressive lenses, also called progressive addition, correct eyesight for things at many distances, just like previously discussed multifocal lenses. The only difference is that they accomplish it without having visible lines dividing the lens’s various zones. (Wow, that’s cool. Find out the way progressive lenses operate if you’re interested.)

5. Prescription Abbreviations for Contact Lenses

Contact prescriptions will also contain other special abbreviations (described below) related to their fitment, along with the terminology mentioned above. Visit our more in-depth tutorial for understanding how to interpret a prescription for contacts if you’d like to go deeper.

6. BC

“Base curve” is represented by the acronym “BC.” This measurement describes the ideal curve of the contact lens—steep or flat.

7. DIA

The abbreviation DIA stands for “diameter,” and it describes the contact’s width. Millimeters are used to express the contact lens’s diameter.

OS meaning vs. OD meaning demystified

Having explained the OS and OD meaning, along with several other often used terminology and abbreviations related to eyes, we trust you will be able to easily understand your prescription. So all you have to do is enjoy viewing things more clearly by selecting the ideal pair of contacts or glasses.