The People Who Own the Dark (1976)

Now ... there is nothing between you and ... "the people who own the dark"

A group of rich businessmen and military officers who are partying in an old castle are spared when a nuclear war ravages the earth. When they venture out into the nearest town to search for food and supplies, they find most of the residents blinded, and soon they discover the existence of a sinister group called The People Who Own The Dark.