**Appendix**

3D models were created and used for AR simulations, virtual reality, and advanced mixed reality with Microsoft HoloLens 2 by us in this chapter. This includes the human eyeball with TrueColor confocal fundus image. These models help in better understanding of concepts and can be used in various fields of medicine. We have created models related to ophthalmology, which allows us to explain a disease or a condition with its pathophysiology, pathway, clinical features, tests, treatment and prognosis creatively and interactively.

We have created apps using these models, including the Eye MG AR (https:// play.google.com/store/apps/details?id=com.EyeMG\_AR) and Eye MG 3D (https:// play.google.com/store/apps/details?id=com.EyeMG\_3D) which are based on AR model of the eye and multimodal fundus imaging atlas, respectively. These are available for Android users and are free to download from Google Play Store. An app for iPhone users named Eye MG Max (https://apps.apple.com/in/app/ eye-mg-max/id1607482649) is currently available in App Store. This application provides eyeball with TrueColor confocal fundus images and all structures related to ophthalmology with a user-friendly interface. In Eye MG Max, multiple views with transparency for viewing the structures passing through another model, free camera mode, annotated modes, customized zoomed views and videos related to any ophthalmic pathology are provided; thus, providing a 3D atlas at the user's fingertip for better patient counseling. Usage of mixed reality in ophthalmology is only in the primitive stages.

The same 3D models used in the previously mentioned applications have been imported into Hololens 2 for holographic viewing by medical professionals and patients. When viewed through Hololens 2, the device tracks our hands, eyes and surrounding environment. This enables us to select different holograms just by looking at them (eye-tracking) and move the holograms around and enlarge/shrink using our hands (hand-tracking). This enables us to view the models in a 360-degree 3-Dimensional view. We can use this to counsel patients in a much more efficient and convincing manner, leading to better patient compliance. We can also add components such as Optical Coherence Tomography apart from TrueColor confocal fundus evaluation. Advancements such as holographic surgical simulative training will come out eventually in the near future.
