OET Medical Vocabulary, Word of the Day
Oculus (Eye) – Meaning and Usage in Medical English
Oct
Oculus is the Latin medical term for the eye, seen in prescriptions as O.D. (right eye), O.S. (left eye) and O.U. (both eyes).
Have you ever seen O.D. or O.S. on an eye prescription and wondered what they mean?
Today’s word — Oculus — explains it all.
👁 What Does “Oculus” Mean?
Oculus is a Latin word that means eye.
It appears frequently in terminology and patient records — especially in ophthalmology and optometry.
When you see abbreviations like O.D. or O.S. on a prescription or chart, they come from this word.
🔍 Clinical Usage
In Latin-based medical notation:
| Abbreviation | Latin Term | English Meaning |
|---|---|---|
| O.D. | Oculus Dexter | Right eye |
| O.S. | Oculus Sinister | Left eye |
| O.U. | Oculus Uterque | Both eyes |
You’ll often find Oculus and its abbreviations — O.D., O.S., and O.U. — in patient charts, prescriptions, and ophthalmology notes. They may also come up during eye examinations or training discussions with other healthcare professionals.
Example:
“Apply ointment to O.S. twice daily.” → Apply to the left eye twice a day.
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👉 Watch our 20-second clip: Oculus –Learn how to pronounce it.
🔗 Related Words
Browse every term in our Medical English Body Parts A–Z guide.
