Glass beads as in spheres? Cut a sphere in half and you have a lens, which might do something like this (the pyramidal lenses in the article work like Fresnel lenses).

About the only place I've seen spherical glass beads in use is in retroreflective materials (reflect the majority of incident light back towards the source).

I've seen (effectively) half spheres in use in light diffusion - notably the filter in front of digital camera sensors spreading individual photons across individual sensors making the camera less sensitive to regular hard edges. There's some dispute over whether that's a positive thing, but there it is.

So... links to glass beads, or half glass beads for something like this? I'm fine with optics-tech. Thx!