well, it´s passing through my objects too. if you put a geometry between light and camera, the glowFX seems to disappear. its amount is depending on how much from the directedDiscShape node is visible behind the geometry.

but in the end it´s only a post process. so I´d use opticalFX only when the origin of the light source isn´t covered by something. In reality, is there even a halo effect when light passes through a medium like glas or something?