Part 1 of 2. The text is a little small and fuzzy when you expand it to full screen. You can download the PDF document and follow along with the video narration.
These two videos illustrate an example of a GEMS (General Equivalency Mapping) crosswalk of a top 27 list of Eyecare ICD-9 codes to the correct ICD-10 codes. This applies to both ophthalmology and optometry. The complete 21 page document is available on and is free.