What it means
OS has long been written for the left eye, with OD for the right eye and OU for each eye. ISMP lists all three as error-prone, because they have been read as the ear abbreviations (AS, AD, AU) and the wrong body part was treated. The "os" in "per os" (by mouth) has also been mistaken for left eye. Write "left eye" instead.
For the nurse
Do not write OS. If an eye-drop order uses it, contact the prescriber to confirm which eye before giving the drug.
At a glance
| Abbreviations | OD (right eye) and OU (each eye) are on the same ISMP list |
|---|
Related terms
OD
An abbreviation that has been used for right eye, for once daily and for overdose.