There are multiple definitions:

1. operatiekamer(Dutch)

   • OR
   • Anesthesiology/analgesia, Surgery

2. orthokeratology(English)

   • during sleeping time the use of specially designed and fitted contact lenses to temporarily reshape the cornea to improve vision
   • ASCPS, CSCLR, AL, ALG
   • Ophthalmology
   • https://doi.org…mol-2018-312933
   • https://www.aao…o dental braces