Basically, matt still goes blind at nine and gets enhanced senses 'thanks' to chemicals, but it wasn't in a car accident. It was on purpose. Someone spilled chemicals in his eyes on purpose. (experimentation? vengeance because jack won a fight? serial killer? grandma trying to 'exorcise the Devil'? filler's choice) How does matt grows up with that? How does it affect Daredevil?
Matt, AU where he was blinded on purpose
https://daredevilkink.dreamwidth.org/8773.html?thread=18796101#cmt18796101