No. Dungeon design doesn’t have to depend on darkness in any way. You can light the whole thing as brightly as your living room and get plenty of suspense and horror out of the layout and interior decorating (to put it flippantly). And since we are ourselves a visually oriented species, that means more to show via artwork and description. Unusual angles, use of the third dimension, alcoves and niches, misdirection and perspective tricks, horrible objects and art, and so on - this stuff is all right there.