| IOD | injured on duty; integrated optical density; interorbital distance |
|---|---|
| MORD | magnetic optical rotatory dispersion |
| OCR | oculocardiac reflex; oculocerebrorenal [syndrome]; optical character recognition |
| OD | Doctor of Optometry; obtained absorbance; occipital dysplasia; occupational dermatitis; occupational... |
| ODU | optical density unit |