Thayer David loves that monocle, doesn't he? And he loves dropping it from his eye as he looks up from reading. But it can't be very comfortable to read with a monocle, and it must be very bad for one's eyes.
If Adam killed Barnabas, would Adam then die because of his connection to Barnabas, and would Barnabas become a vampire because Adam was no longer draining the affliction from Barnabas? A nice little boomerang of a murder.
LOL on the boomerang... as for the monocle, I'd guess that a person wears one because only one eye is 'bad', so once he gets used to positioning it correctly, the 'good' eye and corrected eye work fine together.