Are Eschenbach glasses fresnel glasses? And could they be used in an HMD? How about instead of a monitor fresnel? Somehow I don't think the latter would work, but the former should.

They seem to have regular lenses rather than fresnels, but that doesn't mean anything. Fresnel lenses work like regular lenses, they're just flat and light.

The glasses work like very simple binoculars, so yeah, they could be used for enlarging a screen. FOV will probably be limited anyway though, since the lenses look pretty small. On the plus side, you could put any kind of 3d glasses in front of them and it'd still work. An HDTV at a distance would certainly appear larger, and the fact that you can focus the glasses at infinity will probably help too, just like the fresnels do.

Shouldn't this be in the Fresnel thread btw? It's about the same thing really, enlarging the screen for increased immersion.

Never seen those before, but they look interesting.