There are technically answers to this question both here, Sage Advice, a tweet by Jeremy Crawford, and this question here, but they still seem rather vague/non-descriptive enough.
Devil’s Sight (PHB Pg. 110)
You can see normally in darkness, both magical and nonmagical, to a distance of 120 feet.
But does "see normally" imply you see as though everything is naturally lit up by the sun; lit by a dim torch; still dark, but you can pick out clear images, shapes, and details; or something else entirely?