Which Eye Is OD vs. OS<\/h2>\n\n\n\n
First thing\u2019s first\u2014let\u2019s get these eye abbreviations sorted and learn what they stand for. <\/p>\n\n\n\n
OD<\/h3>\n\n\n\n
OD means \u201cright eye.\u201d OD is the traditional abbreviation used for the right eye because it\u2019s short for oculus dexter<\/em>, which means \u201cright eye\u201d in Latin. Sometimes, doctors will just use \u201cRE\u201d or \u201cright\u201d for the right eye.<\/p>\n\n\n\n OS means \u201cleft eye.\u201d OS is the traditional abbreviation for the left eye because it\u2019s short for oculus sinister<\/em>, which is \u201cleft eye\u201d in Latin. Some doctors might just write \u201cleft\u201d or use LE for \u201cleft eye.\u201d<\/p>\n\n\n\n Surprise! Here\u2019s another eye abbreviation you might see on your prescription. OU is an abbreviation for oculus uterque<\/em>, which is Latin for \u201cboth eyes.\u201d<\/p>\n\n\n\n In addition to OD and OS, your eye prescription is bound to feature several other unfamiliar abbreviations. Here\u2019s a handy list of all the commonly used terms that you might encounter when looking over the prescription for your eyeglasses<\/a>.<\/p>\n\n\n\n SPH stands for \u201csphere.\u201d This abbreviation is used if vision correction is needed for either nearsightedness<\/a> or farsightedness<\/a>\u2014or both. The number shown by this abbreviation refers to the lens power you\u2019ll need to correct it.<\/p>\n\n\n\n If the number with this term is negative (indicated with a – symbol), then you\u2019re nearsighted; if the number with this term is positive (indicated with a + symbol), that means you\u2019re farsighted. Some prescriptions may have both positive and negative numbers, meaning you need vision correction for both your near and far vision.<\/p>\n\n\n\n CYL stands for \u201ccylinder,\u201d and it indicates astigmatism<\/a>. You\u2019ll only see a number with CYL if you have an astigmatism to correct. CYL numbers can be positive or negative and refer to the lens power needed to correct the astigmatism. The larger the number, the greater the astigmatism.<\/p>\n\n\n\n \u201cAxis\u201d is measured in degrees and refers to where an astigmatism is found on the cornea of the eye. If you have an astigmatism, there will be numbers in both the CYL and AXIS columns of your prescription.<\/p>\n\n\n\n \u201cAdd\u201d refers to the magnifying power (if any) that is added to the bottom part of a multifocal or progressive lens, most commonly used to correct presbyopia<\/a>.<\/p>\n\n\n\n Your prescription may include a column for \u201cprism<\/a>\u201d or \u201cbase.\u201d These are used in your prescription if a correction is needed for eye misalignment. The base value for a prism correction will be either \u201cin\u201d or \u201cout,\u201d or \u201cup\u201d or \u201cdown.\u201d You might see the abbreviations BI, BO, BU, or BD respectively. You will also see a corresponding prism power associated with the base value.<\/p>\n\n\n\n PD is short for \u201cpupillary distance,\u201d and\u2014you guessed it\u2014it measures the distance between your eyes\u2019 pupils. If your prescription doesn\u2019t include this number, try using our online tool<\/a> to measure your pupillary distance yourself.<\/p>\n\n\n\n Check out our informational article if you’d like to learn more about measuring pupillary distance<\/a>.<\/p>\n\n\n\n Vision prescriptions usually look like a table or chart, with OD and OS along the side for the rows, and the other terms across the top for the columns. It will look something like this.<\/p>\n\n\n\n\n\n There are many different types of lenses for glasses<\/a>, and your doctor may have used abbreviations on your prescription to note which lenses you need. So many confusing letters, we know! Hang in there\u2014we\u2019re almost through.<\/p>\n\n\n\n SV is an abbreviation for \u201csingle vision<\/a>.\u201d This means that the lens comprises only one prescription.<\/p>\n\n\n\n BF stands for \u201cbifocal.\u201d Bifocal lenses<\/a> have two distinct prescriptions\u2014one for seeing objects at a distance (which is at the top of the lens), and one for seeing near objects (placed at the bottom of the lens). You can spot a visible line on the lens, delineating these two areas.<\/p>\n\n\n\n TF is short for \u201ctrifocal.\u201d Trifocal lenses<\/a> are similar to bifocal lenses, but they correct for three areas of vision\u2014distance (at the top of the lens), intermediate (in the middle of the lens), and near (at the bottom of the lens). There is a visible line delineating the three separate areas of the lens.<\/p>\n\n\n\n Like other multifocal lenses, progressives<\/a> (or progressive addition lenses) correct vision for objects at multiple distances, but they do so without any visible lines separating the different zones of the lens. (Cool, huh? If you\u2019re curious, check out how progressive lenses work<\/a>.)<\/p>\n\n\n\n<\/div>\n\nOS<\/h3>\n\n\n\n
OU<\/h3>\n\n\n\n
Glossary of Eyeglass Prescription Abbreviations and Terms<\/h2>\n\n\n\n
SPH<\/h3>\n\n\n\n
CYL<\/h3>\n\n\n\n
Axis<\/h3>\n\n\n\n
Add<\/h3>\n\n\n\n
BI, BO, BU, or BD<\/h3>\n\n\n\n
PD<\/h3>\n\n\n\n
OD and OS on a Vision Prescription<\/h2>\n\n\n\n
Common Lens Type Abbreviations<\/h2>\n\n\n\n
SV<\/h3>\n\n\n\n
BF<\/h3>\n\n\n\n
TF<\/h3>\n\n\n\n
PL or PAL<\/h3>\n\n\n\n
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