What does the abbreviation OS refer to in medical terms?

The abbreviation OS in medical terminology specifically stands for "oculus sinister," which is Latin for "left eye." This term is used in prescriptions and medical records to indicate that treatment or examination pertains to the left eye. Understanding these abbreviations is crucial for healthcare professionals to ensure accurate communication, particularly in contexts such as ophthalmology.

In contrast, other options refer to different anatomical areas. The right eye is abbreviated as OD (oculus dexter), while the left ear is denoted by the abbreviation AS (auris sinistra), and both ears are represented by AU (auris utraque). This precise use of terminology helps avoid confusion and ensures that patients receive the appropriate care in the correct locations.