  Around-device interaction promises to extend the input space of mobile and
wearable devices beyond the common but restricted touchscreen. So far, most
around-device interaction approaches rely on instrumenting the device or the
environment with additional sensors. We believe, that the full potential of
ordinary cameras, specifically user-facing cameras, which are integrated in
most mobile devices today, are not used to their full potential, yet. We To
this end, we present a novel approach for extending the input space around
unmodified mobile devices using built-in front-facing cameras of unmodified
handheld devices. Our approach estimates hand poses and gestures through
reflections in sunglasses, ski goggles or visors. Thereby, GlassHands creates
an enlarged input space, rivaling input reach on large touch displays. We
discuss the idea, its limitations and future work.
