In Glorantha Digest V2 #398, Dane 'Danger' Johnson writes about the effects
of curved light. I can't refute your "bowl appearance" work, but you're
wrong about the wall example for the simple reason that light striking the
wall bounces in all directions, including somewhat down. This light, if it
travelled straight, would hit the ground. However, because it rises toward
the Sky, it intersects your retina instead. Thus you CAN and DO see the top
of the wall. It is the BOTTOM of the wall which, if it is beyond the
horizon, you can't see, because the light striking it can't bend low enough
to simultaneously miss the ground and avoid getting sucked up into the sky
before it reaches you.
Besides which, light works by beams emitted from the eyes, as was formerly
thought to be the case on Earth. Thus, people with stronger eyes can see
further. Farsee actually broadens your horizons because it makes your
eyebeams stronger and they can go farther before they slow down, peter out,
and stream up to the sky.
But what do I know? I'm not a physicist.