The Cow - 2:17
Their situation is like that of those who light a fire: When the fire begins to illuminate their surroundings, Allah removes their light and leaves them in darkness, blind.
Related:
The Light/24:40
Or it is like the darkness in the midst of a vast sea covered by wave after wave with a dense mist. Darkness piled on top of each other. When a man stretches out his hand, he can hardly see it. He whom Allah has deprived of light has no light at all.