Granted. 3d printing of medical devices and brain microchips advance such that these people all get their senses and abilities. They quickly merge with machines by having excess memory in an external hard drive and sutured on personalities from the more advanced ai. Soon humanity is enslaved by the formerly blind, mute, deaf, and paralysed.
Granted. All humans were blind to undefinable-xxx. They now have the third eye seeing with clarity. The visions of cthulu quickly drive all of humanity to extinction.