can't see hand in front of face
can't see (one's) hand in front of (one's) face
Cannot see anything at all due to darkness. Can you turn on the basement light? I can't see my hand in front of my face down here!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
can't see one's hand in front of one's face
Fig. [to be] unable to see very far, usually due to darkness or fog. (Also with cannot.) It was so dark that I couldn't see my hand in front of my face. Bob said that the fog was so thick he couldn't see his hand in front of his face.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.