Author’s Disclosure Block: Edsel Ing, none; Ishaan Roy, none; Mahdi Tavakoli, none; Imran Jivraj, none; Alberto Galvez Ruiz, none

Abstract Body
Purpose: To develop mixed reality glasses (MRG) software to help patients with hemianopsia better navigate their visual environment. Study Design: Evolutionary (Prototype) Methods: Unlike virtual reality, mixed reality allows users to see the actual environment plus superimposed holograms. We employed the commercially available Microsoft HoloLens 2 MRG ($5000 US) in research mode, and the Unity software platform to develop real-time picture-in-picture navigation (PIPN). With PIPNa miniaturized view of the visual environment is transposed to the edge of theintact visual field inpatients with hemianopsia. External remote control was developed with the Streamlit and WebSockets applications as the MRG may be difficult for patients to initialize. Results: We were able to transpose a real-time miniaturized full-field picture-in-picture (PIP) hologram to the right or left and top or bottom of the MRG. The PIP could be adjusted to either black and white or color. Sighted observers using hemianopic simulator goggles found that PIPN did not impair navigation ability and was easy to adapt to once initialized. MRG could be worn over spectacles, but pantoscopic tilt required adjustment of the viewing window. Fully charged, the run times were at least one hour. REB approval for testing on patients was obtained. Conclusion: PIPN is a viable rehabilitation option to improve navigation for patients with hemianopsia and may be combined with other technologies such as obstacle detection. Other potential applications for MRG vision rehabilitation include patients with torsional diplopia, and oscillopsia. (CC-BY-NC-ND)