Lights Off Reading Riddle
Riddle: Joe and Sally were sitting in their family room one night. While Joe was watching T.V, his wife Sally was reading. All of a sudden the power went out and Joe decided to go to bed, but Sally kept on reading. With no use of artificial light, Sally kept on reading. How?
Answer: Sally was blind, she was reading a book by Braille.
Source: https://www.riddles.com/322
