There is a simple idea at the heart of the HOE (Holographic Optical Element) AR combiner argument that often gets lost in the technical debate: AR glasses are, fundamentally, glasses first. If you hold onto that idea, the question of which optical combiner to use for AR glasses becomes much clearer. The combiner — the lens element that blends digital content into the user’s view of the real world — should start from where glasses already are: the conventional curved spectacle lens that billions of people already wear and that the industry already manufa…