This is important.
Or his god wouldn't be showing it to him.
Any negative effects it has on him should already have been taken into account.
Keltham tries to look around.
Very briefly.
It's still enough to get a general impression of things.
He looks at Carissa, who doesn't seem to be in visible emotional difficulty, because six years at the Worldwound, presumably.
"Please look around to see if there are any clues and then turn this off," Keltham says, and shuts his eyes and puts his fingers into his ears.
Illusion spell. This isn't real. A movie of a bad thing that isn't actually happening.