Autistic Alex can see through all of Dave's masquerades.
Alex: "Dave, is that you?"
Zig Zagged: ???
Averted: Bob's blindness does not protect him from mind control.
Enforced: We need to have Alice's pride dented as part of a Humiliation Conga. Let's have someone defeat her with a weakness.
Lampshaded: "Who would have though a blind person would prove a threat to me! The Mistress of gaze attacks!"
Invoked: Bob is recruited specifically to deal with Alice.
Exploited: The Kingdom of Freedonia encourages disabled children to become adventurers for this reason.
Defied: Alice enhances her power to affect blind people.
Discussed: "I got you now Bob!" "Huh, what? I can't hear you! I forgot my hearing aids today!"
Deconstructed: People become aware of Alice's powers, and parents weepingly blind their children on purpose to spare them from Alice the Evil.
Reconstructed: More sensible parents simply teach their children to function blindfolded or with their eyes closed. The Hero is blinded in an accident and becomes the only one who can actually fight while blinded thus making him destined to defeat Alice the Evil.