OU Medical Abbreviation — Definition & Use in Ophthalmology

Understanding ophthalmic abbreviations is essential for accurately interpreting clinical notes and prescriptions. In eye care, Latin-derived terms and specific acronyms such as OD, OS, and OU are routinely used by medical professionals. This article provides a clear explanation of what each abbreviation represents—particularly OU, which refers to both eyes—and outlines how these terms are applied in ophthalmology.

Common Abbreviations in Eye Care

Medical professionals use Latin-based abbreviations to quickly denote which eye or eyes are affected. Here are some of the key abbreviations used in ophthalmology:

AbbreviationFull TermMeaning
OUOculus UterqueBoth Eyes
ODOculus DexterRight Eye
OSOculus SinisterLeft Eye

OU is the abbreviation for “both eyes,” while OD and OS stand for the right eye and left eye, respectively. These abbreviations are essential in optometry, ophthalmology, and when prescribing corrective lenses or treatments.

Complete List of Ophthalmology Abbreviations

For those who want to dive deeper, here is a more comprehensive list of abbreviations related to ophthalmology. These include abbreviations used for diagnosis, treatment, and clinical descriptions.

AbbreviationFull TermMeaning
ACAnterior chamberThe fluid-filled space inside the eye
ALTArgon laser trabeculoplastyA procedure to treat glaucoma
APD, RAPD(Relative) Afferent pupillary defectA pupil abnormality
ARMD, AMDAge-related macular degenerationA common eye condition in older adults
ASCAnterior subcapsular cataractA type of cataract
BDRBackground diabetic retinopathyEarly-stage diabetic eye disease
BRAOBranch retinal artery occlusionBlockage in a branch of the retinal artery
BRVOBranch retinal vein occlusionBlockage in a branch of the retinal vein
CACGChronic angle-closure glaucomaA type of glaucoma
CE/IOLCataract extraction with intraocular lens implantCataract surgery
CNVM, CNVChoroidal neovascular membraneAbnormal blood vessel growth in the eye
CRVOCentral retinal vein occlusionBlockage of the main retinal vein
CSMEClinically significant macular edemaSwelling of the retina
DESDry eye syndromeLack of adequate moisture in the eyes
DSAEKDescemet stripping automated endothelial keratoplastyCorneal transplant procedure
ECCEExtracapsular cataract extractionA method of cataract removal
ERMEpiretinal membraneScar tissue on the retina
HMHand motionVisual acuity test result
IOLIntraocular lensArtificial lens used in cataract surgery
IOPIntraocular pressureFluid pressure inside the eye
LASIKLaser in situ keratomileusisEye surgery to correct vision
LPLight perceptionAbility to perceive light
MDMacular degenerationEye disease that affects central vision
NLPNo light perceptionComplete vision loss
NSNuclear sclerosisHardening of the central eye lens
POAGPrimary open-angle glaucomaA common type of glaucoma
PRKPhotorefractive keratectomyLaser surgery to reshape the cornea
RDRetinal detachmentSeparation of the retina from the back of the eye
VAVisual acuitySharpness of vision
YAGYttrium-aluminum-garnet laserLaser treatment for cataracts

This list is not exhaustive, but it provides an overview of the most common abbreviations you may encounter.

Why Abbreviations Matter

The use of abbreviations in ophthalmology is primarily to ensure efficient and accurate communication between medical professionals. These abbreviations are universally recognized within the field, which reduces the risk of errors when treating patients. However, for patients, these abbreviations can often be confusing. Understanding the meaning of abbreviations like OU, OD, and OS is crucial to properly follow treatment instructions.

An ophthalmology prescription concept illustrating the meaning of the medical abbreviation “OU,” which refers to both eyes in clinical documentation and eye care terminology.

Our Editorial Team’s Advice

Navigating eye care and understanding medical terminology can be challenging, but knowledge is power. If you ever receive a prescription with abbreviations you don’t understand, ask your healthcare provider to clarify. It’s essential for your health and peace of mind to know exactly what treatment you’re receiving and how to use it. Eye care is a team effort between you and your doctor, and informed patients are empowered to make the best decisions for their vision.

How Ophthalmic Abbreviations Are Used in Eye Care

This infographic maps where key abbreviations appear across the patient journey—examination, diagnosis, treatment, and prescriptions—clarifying how terms like VA, IOP, ARMD, PRK, and OU are applied in real clinical workflows without repeating definitions from the article.

Examination Stage
VA IOP APD / RAPD
Measurements and initial findings: visual acuity, intraocular pressure, and pupillary responses recorded during the comprehensive eye exam.
Diagnosis & Record Keeping
ARMD / AMD POAG RD DES
Clinicians document confirmed conditions and exam impressions using standardized shorthand to ensure clarity across providers.
Treatment & Procedures
ALT CE/IOL PRK LASIK YAG
Surgical or therapeutic plans are recorded with procedural abbreviations for precise, concise communication in the operative and outpatient settings.
Prescription & Instructions
OD OS OU
Final eyewear or treatment directives indicate which eye(s) are affected—right, left, or both—ensuring patients follow accurate, eye-specific guidance.
Source: eyexan.com
Reyus Mammadli/ author of the article

I’m the author and editor of this health blog, active since 2008. With a background in medical and biotechnical devices, I focus on making health and self-care topics—especially in ophthalmology—clear and accessible.

Although I’m not a licensed physician, I’ve spent over 15 years working with medical literature and guidelines, with particular attention to trusted ophthalmic sources such as the American Academy of Ophthalmology, National Eye Institute, and PubMed. I also follow the latest updates in diagnostics and treatment technologies.

My aim is to help readers better understand eye diseases, tests, and treatment options—so they can feel more confident when consulting a doctor.

Note: This blog does not provide medical diagnoses or treatments. It offers clear, reliable health information to support informed conversations with healthcare professionals.