A recent article on Nweon, reports on the presentation by Karl Guttag, an expert in near-eye display technology, at AWE 2023. Guttag discussed the challenges of optical MR and video pass-through MR in his 25-minute keynote speech. The article summarizes the main points of Guttag's presentation which highlighted the difficulties in achieving optical MR, including the fixed wavelength of visible light, rough and inaccurate methods for blocking incident light, the need for large field of view and small, lightweight, and low-power devices. Guttag also discussed the advantages and disadvantages of video pass-through MR, such as better virtual image quality, simpler and cheaper optical components, but also limitations such as fixed focus, lower resolution, and alignment issues between cameras and eyes. The article concludes by mentioning that more details of Guttag's presentation, including the video, will be released, and recommends reading a related article on the challenges of MR on the same website.