The Defenders are useless fighting in the dark, except Matt.
Cue Danny essentially forcing the others to take 'lessons' from Matt about being blind.

+ Matt really doesn't want to teach them, mostly because he's too afraid that he'll be like Stick
++ Jessica gets him plastered and only then does he give them a first lesson, all the while barely able to stand up straight
+++++++ Someone gets a wicked headache from trying to focus on listening especially with all the police sirens. Matt just quietly makes them sit down with their head braced because headaches are very common
++++++++++++ Luke walks into a wall, breaks the wall, and doesn't notice because of how hard he's focusing/or injuries